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@ -0,0 +1,207 @@
Author: Charles Fol <folcharles@gmail.com>
Date: Thu Mar 28 12:25:38 2024 -0300
iconv: ISO-2022-CN-EXT: fix out-of-bound writes when writing escape sequence (CVE-2024-2961)
ISO-2022-CN-EXT uses escape sequences to indicate character set changes
(as specified by RFC 1922). While the SOdesignation has the expected
bounds checks, neither SS2designation nor SS3designation have its;
allowing a write overflow of 1, 2, or 3 bytes with fixed values:
'$+I', '$+J', '$+K', '$+L', '$+M', or '$*H'.
Checked on aarch64-linux-gnu.
Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Conflicts:
iconvdata/Makefile
(usual tests conflict)
diff --git a/iconvdata/Makefile b/iconvdata/Makefile
index d5507a048c6a6508..25bd004e7f92a994 100644
--- a/iconvdata/Makefile
+++ b/iconvdata/Makefile
@@ -75,7 +75,7 @@ ifeq (yes,$(build-shared))
tests = bug-iconv1 bug-iconv2 tst-loading tst-e2big tst-iconv4 bug-iconv4 \
tst-iconv6 bug-iconv5 bug-iconv6 tst-iconv7 bug-iconv8 bug-iconv9 \
bug-iconv10 bug-iconv11 bug-iconv12 tst-iconv-big5-hkscs-to-2ucs4 \
- bug-iconv13 bug-iconv14 bug-iconv15
+ bug-iconv13 bug-iconv14 bug-iconv15 tst-iconv-iso-2022-cn-ext
ifeq ($(have-thread-library),yes)
tests += bug-iconv3
endif
@@ -330,6 +330,8 @@ $(objpfx)bug-iconv14.out: $(addprefix $(objpfx), $(gconv-modules)) \
$(addprefix $(objpfx),$(modules.so))
$(objpfx)bug-iconv15.out: $(addprefix $(objpfx), $(gconv-modules)) \
$(addprefix $(objpfx),$(modules.so))
+$(objpfx)tst-iconv-iso-2022-cn-ext.out: $(addprefix $(objpfx), $(gconv-modules)) \
+ $(addprefix $(objpfx),$(modules.so))
$(objpfx)iconv-test.out: run-iconv-test.sh \
$(addprefix $(objpfx), $(gconv-modules)) \
diff --git a/iconvdata/iso-2022-cn-ext.c b/iconvdata/iso-2022-cn-ext.c
index 2aca91c021f21ba0..c1339fe933d9d1c4 100644
--- a/iconvdata/iso-2022-cn-ext.c
+++ b/iconvdata/iso-2022-cn-ext.c
@@ -575,6 +575,12 @@ DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
{ \
const char *escseq; \
\
+ if (outptr + 4 > outend) \
+ { \
+ result = __GCONV_FULL_OUTPUT; \
+ break; \
+ } \
+ \
assert (used == CNS11643_2_set); /* XXX */ \
escseq = "*H"; \
*outptr++ = ESC; \
@@ -588,6 +594,12 @@ DIAG_IGNORE_Os_NEEDS_COMMENT (5, "-Wmaybe-uninitialized");
{ \
const char *escseq; \
\
+ if (outptr + 4 > outend) \
+ { \
+ result = __GCONV_FULL_OUTPUT; \
+ break; \
+ } \
+ \
assert ((used >> 5) >= 3 && (used >> 5) <= 7); \
escseq = "+I+J+K+L+M" + ((used >> 5) - 3) * 2; \
*outptr++ = ESC; \
diff --git a/iconvdata/tst-iconv-iso-2022-cn-ext.c b/iconvdata/tst-iconv-iso-2022-cn-ext.c
new file mode 100644
index 0000000000000000..96a8765fd5369681
--- /dev/null
+++ b/iconvdata/tst-iconv-iso-2022-cn-ext.c
@@ -0,0 +1,128 @@
+/* Verify ISO-2022-CN-EXT does not write out of the bounds.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <errno.h>
+#include <iconv.h>
+#include <sys/mman.h>
+
+#include <support/xunistd.h>
+#include <support/check.h>
+#include <support/support.h>
+
+/* The test sets up a two memory page buffer with the second page marked
+ PROT_NONE to trigger a fault if the conversion writes beyond the exact
+ expected amount. Then we carry out various conversions and precisely
+ place the start of the output buffer in order to trigger a SIGSEGV if the
+ process writes anywhere between 1 and page sized bytes more (only one
+ PROT_NONE page is setup as a canary) than expected. These tests exercise
+ all three of the cases in ISO-2022-CN-EXT where the converter must switch
+ character sets and may run out of buffer space while doing the
+ operation. */
+
+static int
+do_test (void)
+{
+ iconv_t cd = iconv_open ("ISO-2022-CN-EXT", "UTF-8");
+ TEST_VERIFY_EXIT (cd != (iconv_t) -1);
+
+ char *ntf;
+ size_t ntfsize;
+ char *outbufbase;
+ {
+ int pgz = getpagesize ();
+ TEST_VERIFY_EXIT (pgz > 0);
+ ntfsize = 2 * pgz;
+
+ ntf = xmmap (NULL, ntfsize, PROT_READ | PROT_WRITE, MAP_PRIVATE
+ | MAP_ANONYMOUS, -1);
+ xmprotect (ntf + pgz, pgz, PROT_NONE);
+
+ outbufbase = ntf + pgz;
+ }
+
+ /* Check if SOdesignation escape sequence does not trigger an OOB write. */
+ {
+ char inbuf[] = "\xe4\xba\xa4\xe6\x8d\xa2";
+
+ for (int i = 0; i < 9; i++)
+ {
+ char *inp = inbuf;
+ size_t inleft = sizeof (inbuf) - 1;
+
+ char *outp = outbufbase - i;
+ size_t outleft = i;
+
+ TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
+ == (size_t) -1);
+ TEST_COMPARE (errno, E2BIG);
+
+ TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
+ }
+ }
+
+ /* Same as before for SS2designation. */
+ {
+ char inbuf[] = "㴽 \xe3\xb4\xbd";
+
+ for (int i = 0; i < 14; i++)
+ {
+ char *inp = inbuf;
+ size_t inleft = sizeof (inbuf) - 1;
+
+ char *outp = outbufbase - i;
+ size_t outleft = i;
+
+ TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
+ == (size_t) -1);
+ TEST_COMPARE (errno, E2BIG);
+
+ TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
+ }
+ }
+
+ /* Same as before for SS3designation. */
+ {
+ char inbuf[] = "劄 \xe5\x8a\x84";
+
+ for (int i = 0; i < 14; i++)
+ {
+ char *inp = inbuf;
+ size_t inleft = sizeof (inbuf) - 1;
+
+ char *outp = outbufbase - i;
+ size_t outleft = i;
+
+ TEST_VERIFY_EXIT (iconv (cd, &inp, &inleft, &outp, &outleft)
+ == (size_t) -1);
+ TEST_COMPARE (errno, E2BIG);
+
+ TEST_VERIFY_EXIT (iconv (cd, NULL, NULL, NULL, NULL) == 0);
+ }
+ }
+
+ TEST_VERIFY_EXIT (iconv_close (cd) != -1);
+
+ xmunmap (ntf, ntfsize);
+
+ return 0;
+}
+
+#include <support/test-driver.c>

@ -0,0 +1,31 @@
commit 87801a8fd06db1d654eea3e4f7626ff476a9bdaa
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Apr 25 15:00:45 2024 +0200
CVE-2024-33599: nscd: Stack-based buffer overflow in netgroup cache (bug 31677)
Using alloca matches what other caches do. The request length is
bounded by MAXKEYLEN.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index 2f71bf2999dad56b..f13a11b4c4fe3d99 100644
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -503,12 +503,13 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
= (struct indataset *) mempool_alloc (db,
sizeof (*dataset) + req->key_len,
1);
- struct indataset dataset_mem;
bool cacheable = true;
if (__glibc_unlikely (dataset == NULL))
{
cacheable = false;
- dataset = &dataset_mem;
+ /* The alloca is safe because nscd_run_worker verfies that
+ key_len is not larger than MAXKEYLEN. */
+ dataset = alloca (sizeof (*dataset) + req->key_len);
}
datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len,

@ -0,0 +1,52 @@
commit 7835b00dbce53c3c87bbbb1754a95fb5e58187aa
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Apr 25 15:01:07 2024 +0200
CVE-2024-33600: nscd: Do not send missing not-found response in addgetnetgrentX (bug 31678)
If we failed to add a not-found response to the cache, the dataset
point can be null, resulting in a null pointer dereference.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index f13a11b4c4fe3d99..08668e96a9fd2c77 100644
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -148,7 +148,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
/* No such service. */
cacheable = do_notfound (db, fd, req, key, &dataset, &total, &timeout,
&key_copy);
- goto writeout;
+ goto maybe_cache_add;
}
memset (&data, '\0', sizeof (data));
@@ -349,7 +349,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
{
cacheable = do_notfound (db, fd, req, key, &dataset, &total, &timeout,
&key_copy);
- goto writeout;
+ goto maybe_cache_add;
}
total = buffilled;
@@ -411,14 +411,12 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
}
if (he == NULL && fd != -1)
- {
- /* We write the dataset before inserting it to the database
- since while inserting this thread might block and so would
- unnecessarily let the receiver wait. */
- writeout:
+ /* We write the dataset before inserting it to the database since
+ while inserting this thread might block and so would
+ unnecessarily let the receiver wait. */
writeall (fd, &dataset->resp, dataset->head.recsize);
- }
+ maybe_cache_add:
if (cacheable)
{
/* If necessary, we also propagate the data to disk. */

@ -0,0 +1,53 @@
commit b048a482f088e53144d26a61c390bed0210f49f2
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Apr 25 15:01:07 2024 +0200
CVE-2024-33600: nscd: Avoid null pointer crashes after notfound response (bug 31678)
The addgetnetgrentX call in addinnetgrX may have failed to produce
a result, so the result variable in addinnetgrX can be NULL.
Use db->negtimeout as the fallback value if there is no result data;
the timeout is also overwritten below.
Also avoid sending a second not-found response. (The client
disconnects after receiving the first response, so the data stream did
not go out of sync even without this fix.) It is still beneficial to
add the negative response to the mapping, so that the client can get
it from there in the future, instead of going through the socket.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index 08668e96a9fd2c77..5ed16f871c433531 100644
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -512,14 +512,15 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len,
sizeof (innetgroup_response_header),
- he == NULL ? 0 : dh->nreloads + 1, result->head.ttl);
+ he == NULL ? 0 : dh->nreloads + 1,
+ result == NULL ? db->negtimeout : result->head.ttl);
/* Set the notfound status and timeout based on the result from
getnetgrent. */
- dataset->head.notfound = result->head.notfound;
+ dataset->head.notfound = result == NULL || result->head.notfound;
dataset->head.timeout = timeout;
dataset->resp.version = NSCD_VERSION;
- dataset->resp.found = result->resp.found;
+ dataset->resp.found = result != NULL && result->resp.found;
/* Until we find a matching entry the result is 0. */
dataset->resp.result = 0;
@@ -567,7 +568,9 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
goto out;
}
- if (he == NULL)
+ /* addgetnetgrentX may have already sent a notfound response. Do
+ not send another one. */
+ if (he == NULL && dataset->resp.found)
{
/* We write the dataset before inserting it to the database
since while inserting this thread might block and so would

@ -0,0 +1,383 @@
commit c04a21e050d64a1193a6daab872bca2528bda44b
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Apr 25 15:01:07 2024 +0200
CVE-2024-33601, CVE-2024-33602: nscd: netgroup: Use two buffers in addgetnetgrentX (bug 31680)
This avoids potential memory corruption when the underlying NSS
callback function does not use the buffer space to store all strings
(e.g., for constant strings).
Instead of custom buffer management, two scratch buffers are used.
This increases stack usage somewhat.
Scratch buffer allocation failure is handled by return -1
(an invalid timeout value) instead of terminating the process.
This fixes bug 31679.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index 5ed16f871c433531..92c9cb36fb00d72e 100644
--- a/nscd/netgroupcache.c
+++ b/nscd/netgroupcache.c
@@ -24,6 +24,7 @@
#include <stdlib.h>
#include <unistd.h>
#include <sys/mman.h>
+#include <scratch_buffer.h>
#include "../inet/netgroup.h"
#include "nscd.h"
@@ -66,6 +67,16 @@ struct dataset
char strdata[0];
};
+/* Send a notfound response to FD. Always returns -1 to indicate an
+ ephemeral error. */
+static time_t
+send_notfound (int fd)
+{
+ if (fd != -1)
+ TEMP_FAILURE_RETRY (send (fd, &notfound, sizeof (notfound), MSG_NOSIGNAL));
+ return -1;
+}
+
/* Sends a notfound message and prepares a notfound dataset to write to the
cache. Returns true if there was enough memory to allocate the dataset and
returns the dataset in DATASETP, total bytes to write in TOTALP and the
@@ -84,8 +95,7 @@ do_notfound (struct database_dyn *db, int fd, request_header *req,
total = sizeof (notfound);
timeout = time (NULL) + db->negtimeout;
- if (fd != -1)
- TEMP_FAILURE_RETRY (send (fd, &notfound, total, MSG_NOSIGNAL));
+ send_notfound (fd);
dataset = mempool_alloc (db, sizeof (struct dataset) + req->key_len, 1);
/* If we cannot permanently store the result, so be it. */
@@ -110,11 +120,78 @@ do_notfound (struct database_dyn *db, int fd, request_header *req,
return cacheable;
}
+struct addgetnetgrentX_scratch
+{
+ /* This is the result that the caller should use. It can be NULL,
+ point into buffer, or it can be in the cache. */
+ struct dataset *dataset;
+
+ struct scratch_buffer buffer;
+
+ /* Used internally in addgetnetgrentX as a staging area. */
+ struct scratch_buffer tmp;
+
+ /* Number of bytes in buffer that are actually used. */
+ size_t buffer_used;
+};
+
+static void
+addgetnetgrentX_scratch_init (struct addgetnetgrentX_scratch *scratch)
+{
+ scratch->dataset = NULL;
+ scratch_buffer_init (&scratch->buffer);
+ scratch_buffer_init (&scratch->tmp);
+
+ /* Reserve space for the header. */
+ scratch->buffer_used = sizeof (struct dataset);
+ static_assert (sizeof (struct dataset) < sizeof (scratch->tmp.__space),
+ "initial buffer space");
+ memset (scratch->tmp.data, 0, sizeof (struct dataset));
+}
+
+static void
+addgetnetgrentX_scratch_free (struct addgetnetgrentX_scratch *scratch)
+{
+ scratch_buffer_free (&scratch->buffer);
+ scratch_buffer_free (&scratch->tmp);
+}
+
+/* Copy LENGTH bytes from S into SCRATCH. Returns NULL if SCRATCH
+ could not be resized, otherwise a pointer to the copy. */
+static char *
+addgetnetgrentX_append_n (struct addgetnetgrentX_scratch *scratch,
+ const char *s, size_t length)
+{
+ while (true)
+ {
+ size_t remaining = scratch->buffer.length - scratch->buffer_used;
+ if (remaining >= length)
+ break;
+ if (!scratch_buffer_grow_preserve (&scratch->buffer))
+ return NULL;
+ }
+ char *copy = scratch->buffer.data + scratch->buffer_used;
+ memcpy (copy, s, length);
+ scratch->buffer_used += length;
+ return copy;
+}
+
+/* Copy S into SCRATCH, including its null terminator. Returns false
+ if SCRATCH could not be resized. */
+static bool
+addgetnetgrentX_append (struct addgetnetgrentX_scratch *scratch, const char *s)
+{
+ if (s == NULL)
+ s = "";
+ return addgetnetgrentX_append_n (scratch, s, strlen (s) + 1) != NULL;
+}
+
+/* Caller must initialize and free *SCRATCH. If the return value is
+ negative, this function has sent a notfound response. */
static time_t
addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
const char *key, uid_t uid, struct hashentry *he,
- struct datahead *dh, struct dataset **resultp,
- void **tofreep)
+ struct datahead *dh, struct addgetnetgrentX_scratch *scratch)
{
if (__glibc_unlikely (debug_level > 0))
{
@@ -133,14 +210,10 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
char *key_copy = NULL;
struct __netgrent data;
- size_t buflen = MAX (1024, sizeof (*dataset) + req->key_len);
- size_t buffilled = sizeof (*dataset);
- char *buffer = NULL;
size_t nentries = 0;
size_t group_len = strlen (key) + 1;
struct name_list *first_needed
= alloca (sizeof (struct name_list) + group_len);
- *tofreep = NULL;
if (netgroup_database == NULL
&& !__nss_database_get (nss_database_netgroup, &netgroup_database))
@@ -152,8 +225,6 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
}
memset (&data, '\0', sizeof (data));
- buffer = xmalloc (buflen);
- *tofreep = buffer;
first_needed->next = first_needed;
memcpy (first_needed->name, key, group_len);
data.needed_groups = first_needed;
@@ -196,8 +267,8 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
while (1)
{
int e;
- status = getfct.f (&data, buffer + buffilled,
- buflen - buffilled - req->key_len, &e);
+ status = getfct.f (&data, scratch->tmp.data,
+ scratch->tmp.length, &e);
if (status == NSS_STATUS_SUCCESS)
{
if (data.type == triple_val)
@@ -205,68 +276,10 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
const char *nhost = data.val.triple.host;
const char *nuser = data.val.triple.user;
const char *ndomain = data.val.triple.domain;
-
- size_t hostlen = strlen (nhost ?: "") + 1;
- size_t userlen = strlen (nuser ?: "") + 1;
- size_t domainlen = strlen (ndomain ?: "") + 1;
-
- if (nhost == NULL || nuser == NULL || ndomain == NULL
- || nhost > nuser || nuser > ndomain)
- {
- const char *last = nhost;
- if (last == NULL
- || (nuser != NULL && nuser > last))
- last = nuser;
- if (last == NULL
- || (ndomain != NULL && ndomain > last))
- last = ndomain;
-
- size_t bufused
- = (last == NULL
- ? buffilled
- : last + strlen (last) + 1 - buffer);
-
- /* We have to make temporary copies. */
- size_t needed = hostlen + userlen + domainlen;
-
- if (buflen - req->key_len - bufused < needed)
- {
- buflen += MAX (buflen, 2 * needed);
- /* Save offset in the old buffer. We don't
- bother with the NULL check here since
- we'll do that later anyway. */
- size_t nhostdiff = nhost - buffer;
- size_t nuserdiff = nuser - buffer;
- size_t ndomaindiff = ndomain - buffer;
-
- char *newbuf = xrealloc (buffer, buflen);
- /* Fix up the triplet pointers into the new
- buffer. */
- nhost = (nhost ? newbuf + nhostdiff
- : NULL);
- nuser = (nuser ? newbuf + nuserdiff
- : NULL);
- ndomain = (ndomain ? newbuf + ndomaindiff
- : NULL);
- *tofreep = buffer = newbuf;
- }
-
- nhost = memcpy (buffer + bufused,
- nhost ?: "", hostlen);
- nuser = memcpy ((char *) nhost + hostlen,
- nuser ?: "", userlen);
- ndomain = memcpy ((char *) nuser + userlen,
- ndomain ?: "", domainlen);
- }
-
- char *wp = buffer + buffilled;
- wp = memmove (wp, nhost ?: "", hostlen);
- wp += hostlen;
- wp = memmove (wp, nuser ?: "", userlen);
- wp += userlen;
- wp = memmove (wp, ndomain ?: "", domainlen);
- wp += domainlen;
- buffilled = wp - buffer;
+ if (!(addgetnetgrentX_append (scratch, nhost)
+ && addgetnetgrentX_append (scratch, nuser)
+ && addgetnetgrentX_append (scratch, ndomain)))
+ return send_notfound (fd);
++nentries;
}
else
@@ -318,8 +331,8 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
}
else if (status == NSS_STATUS_TRYAGAIN && e == ERANGE)
{
- buflen *= 2;
- *tofreep = buffer = xrealloc (buffer, buflen);
+ if (!scratch_buffer_grow (&scratch->tmp))
+ return send_notfound (fd);
}
else if (status == NSS_STATUS_RETURN
|| status == NSS_STATUS_NOTFOUND
@@ -352,10 +365,17 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
goto maybe_cache_add;
}
- total = buffilled;
+ /* Capture the result size without the key appended. */
+ total = scratch->buffer_used;
+
+ /* Make a copy of the key. The scratch buffer must not move after
+ this point. */
+ key_copy = addgetnetgrentX_append_n (scratch, key, req->key_len);
+ if (key_copy == NULL)
+ return send_notfound (fd);
/* Fill in the dataset. */
- dataset = (struct dataset *) buffer;
+ dataset = scratch->buffer.data;
timeout = datahead_init_pos (&dataset->head, total + req->key_len,
total - offsetof (struct dataset, resp),
he == NULL ? 0 : dh->nreloads + 1,
@@ -364,11 +384,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
dataset->resp.version = NSCD_VERSION;
dataset->resp.found = 1;
dataset->resp.nresults = nentries;
- dataset->resp.result_len = buffilled - sizeof (*dataset);
-
- assert (buflen - buffilled >= req->key_len);
- key_copy = memcpy (buffer + buffilled, key, req->key_len);
- buffilled += req->key_len;
+ dataset->resp.result_len = total - sizeof (*dataset);
/* Now we can determine whether on refill we have to create a new
record or not. */
@@ -399,7 +415,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
if (__glibc_likely (newp != NULL))
{
/* Adjust pointer into the memory block. */
- key_copy = (char *) newp + (key_copy - buffer);
+ key_copy = (char *) newp + (key_copy - (char *) dataset);
dataset = memcpy (newp, dataset, total + req->key_len);
cacheable = true;
@@ -440,7 +456,7 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
}
out:
- *resultp = dataset;
+ scratch->dataset = dataset;
return timeout;
}
@@ -461,6 +477,9 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
if (user != NULL)
key = (char *) rawmemchr (key, '\0') + 1;
const char *domain = *key++ ? key : NULL;
+ struct addgetnetgrentX_scratch scratch;
+
+ addgetnetgrentX_scratch_init (&scratch);
if (__glibc_unlikely (debug_level > 0))
{
@@ -476,12 +495,8 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
group, group_len,
db, uid);
time_t timeout;
- void *tofree;
if (result != NULL)
- {
- timeout = result->head.timeout;
- tofree = NULL;
- }
+ timeout = result->head.timeout;
else
{
request_header req_get =
@@ -490,7 +505,10 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
.key_len = group_len
};
timeout = addgetnetgrentX (db, -1, &req_get, group, uid, NULL, NULL,
- &result, &tofree);
+ &scratch);
+ result = scratch.dataset;
+ if (timeout < 0)
+ goto out;
}
struct indataset
@@ -604,7 +622,7 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
}
out:
- free (tofree);
+ addgetnetgrentX_scratch_free (&scratch);
return timeout;
}
@@ -614,11 +632,12 @@ addgetnetgrentX_ignore (struct database_dyn *db, int fd, request_header *req,
const char *key, uid_t uid, struct hashentry *he,
struct datahead *dh)
{
- struct dataset *ignore;
- void *tofree;
- time_t timeout = addgetnetgrentX (db, fd, req, key, uid, he, dh,
- &ignore, &tofree);
- free (tofree);
+ struct addgetnetgrentX_scratch scratch;
+ addgetnetgrentX_scratch_init (&scratch);
+ time_t timeout = addgetnetgrentX (db, fd, req, key, uid, he, dh, &scratch);
+ addgetnetgrentX_scratch_free (&scratch);
+ if (timeout < 0)
+ timeout = 0;
return timeout;
}
@@ -662,5 +681,9 @@ readdinnetgr (struct database_dyn *db, struct hashentry *he,
.key_len = he->len
};
- return addinnetgrX (db, -1, &req, db->data + he->key, he->owner, he, dh);
+ int timeout = addinnetgrX (db, -1, &req, db->data + he->key, he->owner,
+ he, dh);
+ if (timeout < 0)
+ timeout = 0;
+ return timeout;
}

@ -0,0 +1,43 @@
commit afe42e935b3ee97bac9a7064157587777259c60e
Author: Florian Weimer <fweimer@redhat.com>
Date: Mon Jun 3 10:49:40 2024 +0200
elf: Avoid some free (NULL) calls in _dl_update_slotinfo
This has been confirmed to work around some interposed mallocs. Here
is a discussion of the impact test ust/libc-wrapper/test_libc-wrapper
in lttng-tools:
New TLS usage in libgcc_s.so.1, compatibility impact
<https://inbox.sourceware.org/libc-alpha/8734v1ieke.fsf@oldenburg.str.redhat.com/>
Reportedly, this patch also papers over a similar issue when tcmalloc
2.9.1 is not compiled with -ftls-model=initial-exec. Of course the
goal really should be to compile mallocs with the initial-exec TLS
model, but this commit appears to be a useful interim workaround.
Fixes commit d2123d68275acc0f061e73d5f86ca504e0d5a344 ("elf: Fix slow
tls access after dlopen [BZ #19924]").
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
index 7b3dd9ab60..670dbc42fc 100644
--- a/elf/dl-tls.c
+++ b/elf/dl-tls.c
@@ -819,7 +819,14 @@ _dl_update_slotinfo (unsigned long int req_modid, size_t new_gen)
dtv entry free it. Note: this is not AS-safe. */
/* XXX Ideally we will at some point create a memory
pool. */
- free (dtv[modid].pointer.to_free);
+ /* Avoid calling free on a null pointer. Some mallocs
+ incorrectly use dynamic TLS, and depending on how the
+ free function was compiled, it could call
+ __tls_get_addr before the null pointer check in the
+ free implementation. Checking here papers over at
+ least some dynamic TLS usage by interposed mallocs. */
+ if (dtv[modid].pointer.to_free != NULL)
+ free (dtv[modid].pointer.to_free);
dtv[modid].pointer.val = TLS_DTV_UNALLOCATED;
dtv[modid].pointer.to_free = NULL;

@ -0,0 +1,500 @@
commit 018f0fc3b818d4d1460a4e2384c24802504b1d20
Author: Florian Weimer <fweimer@redhat.com>
Date: Mon Jul 1 17:42:04 2024 +0200
elf: Support recursive use of dynamic TLS in interposed malloc
It turns out that quite a few applications use bundled mallocs that
have been built to use global-dynamic TLS (instead of the recommended
initial-exec TLS). The previous workaround from
commit afe42e935b3ee97bac9a7064157587777259c60e ("elf: Avoid some
free (NULL) calls in _dl_update_slotinfo") does not fix all
encountered cases unfortunatelly.
This change avoids the TLS generation update for recursive use
of TLS from a malloc that was called during a TLS update. This
is possible because an interposed malloc has a fixed module ID and
TLS slot. (It cannot be unloaded.) If an initially-loaded module ID
is encountered in __tls_get_addr and the dynamic linker is already
in the middle of a TLS update, use the outdated DTV, thus avoiding
another call into malloc. It's still necessary to update the
DTV to the most recent generation, to get out of the slow path,
which is why the check for recursion is needed.
The bookkeeping is done using a global counter instead of per-thread
flag because TLS access in the dynamic linker is tricky.
All this will go away once the dynamic linker stops using malloc
for TLS, likely as part of a change that pre-allocates all TLS
during pthread_create/dlopen.
Fixes commit d2123d68275acc0f061e73d5f86ca504e0d5a344 ("elf: Fix slow
tls access after dlopen [BZ #19924]").
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Conflicts:
elf/Makefile - tests and module-names differences
diff -Nrup a/elf/Makefile b/elf/Makefile
--- a/elf/Makefile 2024-07-09 22:06:30.237752048 -0400
+++ b/elf/Makefile 2024-07-10 14:09:02.996759220 -0400
@@ -423,6 +423,7 @@ tests += \
tst-nodeps2 \
tst-noload \
tst-null-argv \
+ tst-recursive-tls \
tst-relsort1 \
tst-ro-dynamic \
tst-rtld-run-static \
@@ -783,6 +784,23 @@ modules-names = \
tst-nodeps1-mod \
tst-nodeps2-mod \
tst-null-argv-lib \
+ tst-recursive-tlsmallocmod \
+ tst-recursive-tlsmod0 \
+ tst-recursive-tlsmod1 \
+ tst-recursive-tlsmod2 \
+ tst-recursive-tlsmod3 \
+ tst-recursive-tlsmod4 \
+ tst-recursive-tlsmod5 \
+ tst-recursive-tlsmod6 \
+ tst-recursive-tlsmod7 \
+ tst-recursive-tlsmod8 \
+ tst-recursive-tlsmod9 \
+ tst-recursive-tlsmod10 \
+ tst-recursive-tlsmod11 \
+ tst-recursive-tlsmod12 \
+ tst-recursive-tlsmod13 \
+ tst-recursive-tlsmod14 \
+ tst-recursive-tlsmod15 \
tst-relsort1mod1 \
tst-relsort1mod2 \
tst-ro-dynamic-mod \
@@ -2725,3 +2743,11 @@ CFLAGS-tst-tlsgap-mod0.c += -mtls-dialec
CFLAGS-tst-tlsgap-mod1.c += -mtls-dialect=gnu2
CFLAGS-tst-tlsgap-mod2.c += -mtls-dialect=gnu2
endif
+
+$(objpfx)tst-recursive-tls: $(objpfx)tst-recursive-tlsmallocmod.so
+# More objects than DTV_SURPLUS, to trigger DTV reallocation.
+$(objpfx)tst-recursive-tls.out: \
+ $(patsubst %,$(objpfx)tst-recursive-tlsmod%.so, \
+ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15)
+$(objpfx)tst-recursive-tlsmod%.os: tst-recursive-tlsmodN.c
+ $(compile-command.c) -DVAR=thread_$* -DFUNC=get_threadvar_$*
diff --git a/elf/dl-tls.c b/elf/dl-tls.c
index 670dbc42fc..3d221273f1 100644
--- a/elf/dl-tls.c
+++ b/elf/dl-tls.c
@@ -75,6 +75,31 @@
/* Default for dl_tls_static_optional. */
#define OPTIONAL_TLS 512
+/* Used to count the number of threads currently executing dynamic TLS
+ updates. Used to avoid recursive malloc calls in __tls_get_addr
+ for an interposed malloc that uses global-dynamic TLS (which is not
+ recommended); see _dl_tls_allocate_active checks. This could be a
+ per-thread flag, but would need TLS access in the dynamic linker. */
+unsigned int _dl_tls_threads_in_update;
+
+static inline void
+_dl_tls_allocate_begin (void)
+{
+ atomic_fetch_add_relaxed (&_dl_tls_threads_in_update, 1);
+}
+
+static inline void
+_dl_tls_allocate_end (void)
+{
+ atomic_fetch_add_relaxed (&_dl_tls_threads_in_update, -1);
+}
+
+static inline bool
+_dl_tls_allocate_active (void)
+{
+ return atomic_load_relaxed (&_dl_tls_threads_in_update) > 0;
+}
+
/* Compute the static TLS surplus based on the namespace count and the
TLS space that can be used for optimizations. */
static inline int
@@ -425,12 +450,18 @@ _dl_allocate_tls_storage (void)
size += TLS_PRE_TCB_SIZE;
#endif
- /* Perform the allocation. Reserve space for the required alignment
- and the pointer to the original allocation. */
+ /* Reserve space for the required alignment and the pointer to the
+ original allocation. */
size_t alignment = GLRO (dl_tls_static_align);
+
+ /* Perform the allocation. */
+ _dl_tls_allocate_begin ();
void *allocated = malloc (size + alignment + sizeof (void *));
if (__glibc_unlikely (allocated == NULL))
- return NULL;
+ {
+ _dl_tls_allocate_end ();
+ return NULL;
+ }
/* Perform alignment and allocate the DTV. */
#if TLS_TCB_AT_TP
@@ -466,6 +497,8 @@ _dl_allocate_tls_storage (void)
result = allocate_dtv (result);
if (result == NULL)
free (allocated);
+
+ _dl_tls_allocate_end ();
return result;
}
@@ -483,6 +516,7 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_modid)
size_t newsize = max_modid + DTV_SURPLUS;
size_t oldsize = dtv[-1].counter;
+ _dl_tls_allocate_begin ();
if (dtv == GL(dl_initial_dtv))
{
/* This is the initial dtv that was either statically allocated in
@@ -502,6 +536,7 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_modid)
if (newp == NULL)
oom ();
}
+ _dl_tls_allocate_end ();
newp[0].counter = newsize;
@@ -676,7 +711,9 @@ allocate_dtv_entry (size_t alignment, size_t size)
if (powerof2 (alignment) && alignment <= _Alignof (max_align_t))
{
/* The alignment is supported by malloc. */
+ _dl_tls_allocate_begin ();
void *ptr = malloc (size);
+ _dl_tls_allocate_end ();
return (struct dtv_pointer) { ptr, ptr };
}
@@ -688,7 +725,10 @@ allocate_dtv_entry (size_t alignment, size_t size)
/* Perform the allocation. This is the pointer we need to free
later. */
+ _dl_tls_allocate_begin ();
void *start = malloc (alloc_size);
+ _dl_tls_allocate_end ();
+
if (start == NULL)
return (struct dtv_pointer) {};
@@ -826,7 +866,11 @@ _dl_update_slotinfo (unsigned long int req_modid, size_t new_gen)
free implementation. Checking here papers over at
least some dynamic TLS usage by interposed mallocs. */
if (dtv[modid].pointer.to_free != NULL)
- free (dtv[modid].pointer.to_free);
+ {
+ _dl_tls_allocate_begin ();
+ free (dtv[modid].pointer.to_free);
+ _dl_tls_allocate_end ();
+ }
dtv[modid].pointer.val = TLS_DTV_UNALLOCATED;
dtv[modid].pointer.to_free = NULL;
@@ -956,10 +1000,22 @@ __tls_get_addr (GET_ADDR_ARGS)
size_t gen = atomic_load_relaxed (&GL(dl_tls_generation));
if (__glibc_unlikely (dtv[0].counter != gen))
{
- /* Update DTV up to the global generation, see CONCURRENCY NOTES
- in _dl_update_slotinfo. */
- gen = atomic_load_acquire (&GL(dl_tls_generation));
- return update_get_addr (GET_ADDR_PARAM, gen);
+ if (_dl_tls_allocate_active ()
+ && GET_ADDR_MODULE < _dl_tls_initial_modid_limit)
+ /* This is a reentrant __tls_get_addr call, but we can
+ satisfy it because it's an initially-loaded module ID.
+ These TLS slotinfo slots do not change, so the
+ out-of-date generation counter does not matter. However,
+ if not in a TLS update, still update_get_addr below, to
+ get off the slow path eventually. */
+ ;
+ else
+ {
+ /* Update DTV up to the global generation, see CONCURRENCY NOTES
+ in _dl_update_slotinfo. */
+ gen = atomic_load_acquire (&GL(dl_tls_generation));
+ return update_get_addr (GET_ADDR_PARAM, gen);
+ }
}
void *p = dtv[GET_ADDR_MODULE].pointer.val;
@@ -969,7 +1025,7 @@ __tls_get_addr (GET_ADDR_ARGS)
return (char *) p + GET_ADDR_OFFSET;
}
-#endif
+#endif /* SHARED */
/* Look up the module's TLS block as for __tls_get_addr,
@@ -1018,6 +1074,25 @@ _dl_tls_get_addr_soft (struct link_map *l)
return data;
}
+size_t _dl_tls_initial_modid_limit;
+
+void
+_dl_tls_initial_modid_limit_setup (void)
+{
+ struct dtv_slotinfo_list *listp = GL(dl_tls_dtv_slotinfo_list);
+ size_t idx;
+ for (idx = 0; idx < listp->len; ++idx)
+ {
+ struct link_map *l = listp->slotinfo[idx].map;
+ if (l == NULL
+ /* The object can be unloaded, so its modid can be
+ reassociated. */
+ || !(l->l_type == lt_executable || l->l_type == lt_library))
+ break;
+ }
+ _dl_tls_initial_modid_limit = idx;
+}
+
void
_dl_add_to_slotinfo (struct link_map *l, bool do_add)
@@ -1050,9 +1125,11 @@ _dl_add_to_slotinfo (struct link_map *l, bool do_add)
the first slot. */
assert (idx == 0);
+ _dl_tls_allocate_begin ();
listp = (struct dtv_slotinfo_list *)
malloc (sizeof (struct dtv_slotinfo_list)
+ TLS_SLOTINFO_SURPLUS * sizeof (struct dtv_slotinfo));
+ _dl_tls_allocate_end ();
if (listp == NULL)
{
/* We ran out of memory while resizing the dtv slotinfo list. */
diff --git a/elf/rtld.c b/elf/rtld.c
index e9525ea987..6352ba76c5 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -788,6 +788,8 @@ init_tls (size_t naudit)
_dl_fatal_printf ("\
cannot allocate TLS data structures for initial thread\n");
+ _dl_tls_initial_modid_limit_setup ();
+
/* Store for detection of the special case by __tls_get_addr
so it knows not to pass this dtv to the normal realloc. */
GL(dl_initial_dtv) = GET_DTV (tcbp);
diff --git a/elf/tst-recursive-tls.c b/elf/tst-recursive-tls.c
new file mode 100644
index 0000000000..716d1f783a
--- /dev/null
+++ b/elf/tst-recursive-tls.c
@@ -0,0 +1,60 @@
+/* Test with interposed malloc with dynamic TLS.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <array_length.h>
+#include <stdio.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+
+/* Defined in tst-recursive-tlsmallocmod.so. */
+extern __thread unsigned int malloc_subsytem_counter;
+
+static int
+do_test (void)
+{
+ /* 16 is large enough to exercise the DTV resizing case. */
+ void *handles[16];
+
+ for (unsigned int i = 0; i < array_length (handles); ++i)
+ {
+ /* Re-use the TLS slot for module 0. */
+ if (i > 0)
+ xdlclose (handles[0]);
+
+ char soname[30];
+ snprintf (soname, sizeof (soname), "tst-recursive-tlsmod%u.so", i);
+ handles[i] = xdlopen (soname, RTLD_NOW);
+
+ if (i > 0)
+ {
+ handles[0] = xdlopen ("tst-recursive-tlsmod0.so", RTLD_NOW);
+ int (*fptr) (void) = xdlsym (handles[0], "get_threadvar_0");
+ /* May trigger TLS storage allocation using malloc. */
+ TEST_COMPARE (fptr (), 0);
+ }
+ }
+
+ for (unsigned int i = 0; i < array_length (handles); ++i)
+ xdlclose (handles[i]);
+
+ printf ("info: malloc subsystem calls: %u\n", malloc_subsytem_counter);
+ TEST_VERIFY (malloc_subsytem_counter > 0);
+ return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/elf/tst-recursive-tlsmallocmod.c b/elf/tst-recursive-tlsmallocmod.c
new file mode 100644
index 0000000000..c24e9945d1
--- /dev/null
+++ b/elf/tst-recursive-tlsmallocmod.c
@@ -0,0 +1,64 @@
+/* Interposed malloc with dynamic TLS.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdlib.h>
+#include <dlfcn.h>
+
+__thread unsigned int malloc_subsytem_counter;
+
+static __typeof (malloc) *malloc_fptr;
+static __typeof (free) *free_fptr;
+static __typeof (calloc) *calloc_fptr;
+static __typeof (realloc) *realloc_fptr;
+
+static void __attribute__ ((constructor))
+init (void)
+{
+ malloc_fptr = dlsym (RTLD_NEXT, "malloc");
+ free_fptr = dlsym (RTLD_NEXT, "free");
+ calloc_fptr = dlsym (RTLD_NEXT, "calloc");
+ realloc_fptr = dlsym (RTLD_NEXT, "realloc");
+}
+
+void *
+malloc (size_t size)
+{
+ ++malloc_subsytem_counter;
+ return malloc_fptr (size);
+}
+
+void
+free (void *ptr)
+{
+ ++malloc_subsytem_counter;
+ return free_fptr (ptr);
+}
+
+void *
+calloc (size_t a, size_t b)
+{
+ ++malloc_subsytem_counter;
+ return calloc_fptr (a, b);
+}
+
+void *
+realloc (void *ptr, size_t size)
+{
+ ++malloc_subsytem_counter;
+ return realloc_fptr (ptr, size);
+}
diff --git a/elf/tst-recursive-tlsmodN.c b/elf/tst-recursive-tlsmodN.c
new file mode 100644
index 0000000000..bb7592aee6
--- /dev/null
+++ b/elf/tst-recursive-tlsmodN.c
@@ -0,0 +1,28 @@
+/* Test module with global-dynamic TLS. Used to trigger DTV reallocation.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* Compiled with VAR and FUNC set via -D. FUNC requires some
+ relocation against TLS variable VAR. */
+
+__thread int VAR;
+
+int
+FUNC (void)
+{
+ return VAR;
+}
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 50f58a60e3..656e8a3fa0 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -1256,6 +1256,20 @@ extern struct link_map *_dl_update_slotinfo (unsigned long int req_modid,
size_t gen)
attribute_hidden;
+/* The last TLS module ID that is initially loaded, plus 1. TLS
+ addresses for modules with IDs lower than that can be obtained from
+ the DTV even if its generation is outdated. */
+extern size_t _dl_tls_initial_modid_limit attribute_hidden attribute_relro;
+
+/* Compute _dl_tls_initial_modid_limit. To be called after initial
+ relocation. */
+void _dl_tls_initial_modid_limit_setup (void) attribute_hidden;
+
+/* Number of threads currently in a TLS update. This is used to
+ detect reentrant __tls_get_addr calls without a per-thread
+ flag. */
+extern unsigned int _dl_tls_threads_in_update attribute_hidden;
+
/* Look up the module's TLS block as for __tls_get_addr,
but never touch anything. Return null if it's not allocated yet. */
extern void *_dl_tls_get_addr_soft (struct link_map *l) attribute_hidden;
diff --git a/sysdeps/x86_64/dl-tls.c b/sysdeps/x86_64/dl-tls.c
index 869023bbba..b3c1e4fcd7 100644
--- a/sysdeps/x86_64/dl-tls.c
+++ b/sysdeps/x86_64/dl-tls.c
@@ -41,7 +41,10 @@ __tls_get_addr_slow (GET_ADDR_ARGS)
dtv_t *dtv = THREAD_DTV ();
size_t gen = atomic_load_acquire (&GL(dl_tls_generation));
- if (__glibc_unlikely (dtv[0].counter != gen))
+ if (__glibc_unlikely (dtv[0].counter != gen)
+ /* See comment in __tls_get_addr in elf/dl-tls.c. */
+ && !(_dl_tls_allocate_active ()
+ && GET_ADDR_MODULE < _dl_tls_initial_modid_limit))
return update_get_addr (GET_ADDR_PARAM, gen);
return tls_get_addr_tail (GET_ADDR_PARAM, dtv, NULL);

@ -0,0 +1,88 @@
commit fe06fb313bddf7e4530056897d4a706606e49377
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Aug 1 23:31:23 2024 +0200
elf: Clarify and invert second argument of _dl_allocate_tls_init
Also remove an outdated comment: _dl_allocate_tls_init is
called as part of pthread_create.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
diff -Nrup a/elf/dl-tls.c b/elf/dl-tls.c
--- a/elf/dl-tls.c 2024-08-21 13:11:01.422983765 -0400
+++ b/elf/dl-tls.c 2024-08-21 12:51:17.789904690 -0400
@@ -558,9 +558,14 @@ _dl_resize_dtv (dtv_t *dtv, size_t max_m
/* Allocate initial TLS. RESULT should be a non-NULL pointer to storage
for the TLS space. The DTV may be resized, and so this function may
call malloc to allocate that space. The loader's GL(dl_load_tls_lock)
- is taken when manipulating global TLS-related data in the loader. */
+ is taken when manipulating global TLS-related data in the loader.
+
+ If MAIN_THREAD, this is the first call during process
+ initialization. In this case, TLS initialization for secondary
+ (audit) namespaces is skipped because that has already been handled
+ by dlopen. */
void *
-_dl_allocate_tls_init (void *result, bool init_tls)
+_dl_allocate_tls_init (void *result, bool main_thread)
{
if (result == NULL)
/* The memory allocation failed. */
@@ -639,7 +644,7 @@ _dl_allocate_tls_init (void *result, boo
because it would already be set by the audit setup. However,
subsequent thread creation would need to follow the default
behaviour. */
- if (map->l_ns != LM_ID_BASE && !init_tls)
+ if (map->l_ns != LM_ID_BASE && main_thread)
continue;
memset (__mempcpy (dest, map->l_tls_initimage,
map->l_tls_initimage_size), '\0',
@@ -667,7 +672,7 @@ _dl_allocate_tls (void *mem)
{
return _dl_allocate_tls_init (mem == NULL
? _dl_allocate_tls_storage ()
- : allocate_dtv (mem), true);
+ : allocate_dtv (mem), false);
}
rtld_hidden_def (_dl_allocate_tls)
diff -Nrup a/elf/rtld.c b/elf/rtld.c
--- a/elf/rtld.c 2024-08-21 13:11:01.422983765 -0400
+++ b/elf/rtld.c 2024-08-21 12:57:33.134783030 -0400
@@ -2485,7 +2485,7 @@ dl_main (const ElfW(Phdr) *phdr,
into the main thread's TLS area, which we allocated above.
Note: thread-local variables must only be accessed after completing
the next step. */
- _dl_allocate_tls_init (tcbp, false);
+ _dl_allocate_tls_init (tcbp, true);
/* And finally install it for the main thread. */
if (! tls_init_tp_called)
diff -Nrup a/nptl/allocatestack.c b/nptl/allocatestack.c
--- a/nptl/allocatestack.c 2024-08-21 13:11:00.640979593 -0400
+++ b/nptl/allocatestack.c 2024-08-21 12:51:17.789904690 -0400
@@ -137,7 +137,7 @@ get_cached_stack (size_t *sizep, void **
memset (dtv, '\0', (dtv[-1].counter + 1) * sizeof (dtv_t));
/* Re-initialize the TLS. */
- _dl_allocate_tls_init (TLS_TPADJ (result), true);
+ _dl_allocate_tls_init (TLS_TPADJ (result), false);
return result;
}
diff -Nrup a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
--- a/sysdeps/generic/ldsodefs.h 2024-08-21 13:11:01.423983770 -0400
+++ b/sysdeps/generic/ldsodefs.h 2024-08-21 13:30:39.072207595 -0400
@@ -1258,10 +1258,8 @@ extern void _dl_get_tls_static_info (siz
extern void _dl_allocate_static_tls (struct link_map *map) attribute_hidden;
-/* These are internal entry points to the two halves of _dl_allocate_tls,
- only used within rtld.c itself at startup time. */
extern void *_dl_allocate_tls_storage (void) attribute_hidden;
-extern void *_dl_allocate_tls_init (void *, bool);
+extern void *_dl_allocate_tls_init (void *result, bool main_thread);
rtld_hidden_proto (_dl_allocate_tls_init)
/* Deallocate memory allocated with _dl_allocate_tls. */

@ -0,0 +1,524 @@
commit 5097cd344fd243fb8deb6dec96e8073753f962f9
Author: Florian Weimer <fweimer@redhat.com>
Date: Thu Aug 1 23:31:30 2024 +0200
elf: Avoid re-initializing already allocated TLS in dlopen (bug 31717)
The old code used l_init_called as an indicator for whether TLS
initialization was complete. However, it is possible that
TLS for an object is initialized, written to, and then dlopen
for this object is called again, and l_init_called is not true at
this point. Previously, this resulted in TLS being initialized
twice, discarding any interim writes (technically introducing a
use-after-free bug even).
This commit introduces an explicit per-object flag, l_tls_in_slotinfo.
It indicates whether _dl_add_to_slotinfo has been called for this
object. This flag is used to avoid double-initialization of TLS.
In update_tls_slotinfo, the first_static_tls micro-optimization
is removed because preserving the initalization flag for subsequent
use by the second loop for static TLS is a bit complicated, and
another per-object flag does not seem to be worth it. Furthermore,
the l_init_called flag is dropped from the second loop (for static
TLS initialization) because l_need_tls_init on its own prevents
double-initialization.
The remaining l_init_called usage in resize_scopes and update_scopes
is just an optimization due to the use of scope_has_map, so it is
not changed in this commit.
The isupper check ensures that libc.so.6 is TLS is not reverted.
Such a revert happens if l_need_tls_init is not cleared in
_dl_allocate_tls_init for the main_thread case, now that
l_init_called is not checked anymore in update_tls_slotinfo
in elf/dl-open.c.
Reported-by: Jonathon Anderson <janderson@rice.edu>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Conflicts:
elf/Makefile - usual tests list differences
diff -Nrup a/elf/Makefile b/elf/Makefile
--- a/elf/Makefile 2024-08-21 14:24:25.311070834 -0400
+++ b/elf/Makefile 2024-08-21 14:16:19.905503937 -0400
@@ -399,6 +399,10 @@ tests += \
tst-dlmopen-dlerror \
tst-dlmopen-gethostbyname \
tst-dlmopen-twice \
+ tst-dlopen-tlsreinit1 \
+ tst-dlopen-tlsreinit2 \
+ tst-dlopen-tlsreinit3 \
+ tst-dlopen-tlsreinit4 \
tst-dlopenfail \
tst-dlopenfail-2 \
tst-dlopenrpath \
@@ -753,6 +757,9 @@ modules-names = \
tst-dlmopen-gethostbyname-mod \
tst-dlmopen-twice-mod1 \
tst-dlmopen-twice-mod2 \
+ tst-dlopen-tlsreinitmod1 \
+ tst-dlopen-tlsreinitmod2 \
+ tst-dlopen-tlsreinitmod3 \
tst-dlopenfaillinkmod \
tst-dlopenfailmod1 \
tst-dlopenfailmod2 \
@@ -2751,3 +2758,26 @@ $(objpfx)tst-recursive-tls.out: \
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15)
$(objpfx)tst-recursive-tlsmod%.os: tst-recursive-tlsmodN.c
$(compile-command.c) -DVAR=thread_$* -DFUNC=get_threadvar_$*
+
+# Order matters here. The test needs the constructor for
+# tst-dlopen-tlsreinitmod2.so to be called first.
+LDFLAGS-tst-dlopen-tlsreinitmod1.so = -Wl,--no-as-needed
+$(objpfx)tst-dlopen-tlsreinitmod1.so: \
+ $(objpfx)tst-dlopen-tlsreinitmod3.so $(objpfx)tst-dlopen-tlsreinitmod2.so
+LDFLAGS-tst-dlopen-tlsreinit2 = -Wl,--no-as-needed
+$(objpfx)tst-dlopen-tlsreinit2: \
+ $(objpfx)tst-dlopen-tlsreinitmod3.so $(objpfx)tst-dlopen-tlsreinitmod2.so
+LDFLAGS-tst-dlopen-tlsreinit4 = -Wl,--no-as-needed
+$(objpfx)tst-dlopen-tlsreinit4: \
+ $(objpfx)tst-dlopen-tlsreinitmod3.so $(objpfx)tst-dlopen-tlsreinitmod2.so
+# tst-dlopen-tlsreinitmod2.so is underlinked and refers to
+# tst-dlopen-tlsreinitmod3.so. The dependency is provided via
+# $(objpfx)tst-dlopen-tlsreinitmod1.so.
+tst-dlopen-tlsreinitmod2.so-no-z-defs = yes
+$(objpfx)tst-dlopen-tlsreinit.out: $(objpfx)tst-dlopen-tlsreinitmod1.so \
+ $(objpfx)tst-dlopen-tlsreinitmod2.so $(objpfx)tst-dlopen-tlsreinitmod3.so
+# Reuse an audit module which provides ample debug logging.
+$(objpfx)tst-dlopen-tlsreinit3.out: $(objpfx)tst-auditmod1.so
+tst-dlopen-tlsreinit3-ENV = LD_AUDIT=$(objpfx)tst-auditmod1.so
+$(objpfx)tst-dlopen-tlsreinit4.out: $(objpfx)tst-auditmod1.so
+tst-dlopen-tlsreinit4-ENV = LD_AUDIT=$(objpfx)tst-auditmod1.so
diff -Nrup a/elf/dl-open.c b/elf/dl-open.c
--- a/elf/dl-open.c 2024-08-21 14:24:25.273070633 -0400
+++ b/elf/dl-open.c 2024-08-21 14:04:52.834912875 -0400
@@ -362,17 +362,8 @@ resize_tls_slotinfo (struct link_map *ne
{
bool any_tls = false;
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
- {
- struct link_map *imap = new->l_searchlist.r_list[i];
-
- /* Only add TLS memory if this object is loaded now and
- therefore is not yet initialized. */
- if (! imap->l_init_called && imap->l_tls_blocksize > 0)
- {
- _dl_add_to_slotinfo (imap, false);
- any_tls = true;
- }
- }
+ if (_dl_add_to_slotinfo (new->l_searchlist.r_list[i], false))
+ any_tls = true;
return any_tls;
}
@@ -382,22 +373,8 @@ resize_tls_slotinfo (struct link_map *ne
static void
update_tls_slotinfo (struct link_map *new)
{
- unsigned int first_static_tls = new->l_searchlist.r_nlist;
for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
- {
- struct link_map *imap = new->l_searchlist.r_list[i];
-
- /* Only add TLS memory if this object is loaded now and
- therefore is not yet initialized. */
- if (! imap->l_init_called && imap->l_tls_blocksize > 0)
- {
- _dl_add_to_slotinfo (imap, true);
-
- if (imap->l_need_tls_init
- && first_static_tls == new->l_searchlist.r_nlist)
- first_static_tls = i;
- }
- }
+ _dl_add_to_slotinfo (new->l_searchlist.r_list[i], true);
size_t newgen = GL(dl_tls_generation) + 1;
if (__glibc_unlikely (newgen == 0))
@@ -409,13 +386,11 @@ TLS generation counter wrapped! Please
/* We need a second pass for static tls data, because
_dl_update_slotinfo must not be run while calls to
_dl_add_to_slotinfo are still pending. */
- for (unsigned int i = first_static_tls; i < new->l_searchlist.r_nlist; ++i)
+ for (unsigned int i = 0; i < new->l_searchlist.r_nlist; ++i)
{
struct link_map *imap = new->l_searchlist.r_list[i];
- if (imap->l_need_tls_init
- && ! imap->l_init_called
- && imap->l_tls_blocksize > 0)
+ if (imap->l_need_tls_init && imap->l_tls_blocksize > 0)
{
/* For static TLS we have to allocate the memory here and
now, but we can delay updating the DTV. */
diff -Nrup a/elf/dl-tls.c b/elf/dl-tls.c
--- a/elf/dl-tls.c 2024-08-21 14:24:25.315070855 -0400
+++ b/elf/dl-tls.c 2024-08-21 14:20:34.569850644 -0400
@@ -638,17 +638,21 @@ _dl_allocate_tls_init (void *result, boo
some platforms use in static programs requires it. */
dtv[map->l_tls_modid].pointer.val = dest;
- /* Copy the initialization image and clear the BSS part. For
- audit modules or dependencies with initial-exec TLS, we can not
- set the initial TLS image on default loader initialization
- because it would already be set by the audit setup. However,
- subsequent thread creation would need to follow the default
- behaviour. */
+ /* Copy the initialization image and clear the BSS part.
+ For audit modules or dependencies with initial-exec TLS,
+ we can not set the initial TLS image on default loader
+ initialization because it would already be set by the
+ audit setup, which uses the dlopen code and already
+ clears l_need_tls_init. Calls with !main_thread from
+ pthread_create need to initialze TLS for the current
+ thread regardless of namespace. */
if (map->l_ns != LM_ID_BASE && main_thread)
continue;
memset (__mempcpy (dest, map->l_tls_initimage,
map->l_tls_initimage_size), '\0',
map->l_tls_blocksize - map->l_tls_initimage_size);
+ if (main_thread)
+ map->l_need_tls_init = 0;
}
total += cnt;
@@ -1105,9 +1109,32 @@ _dl_tls_initial_modid_limit_setup (void)
}
-void
+/* Add module to slot information data. If DO_ADD is false, only the
+ required memory is allocated. Must be called with
+ GL (dl_load_tls_lock) acquired. If the function has already been
+ called for the link map L with !DO_ADD, then this function will not
+ raise an exception, otherwise it is possible that it encounters a
+ memory allocation failure.
+
+ Return false if L has already been added to the slotinfo data, or
+ if L has no TLS data. If the returned value is true, L has been
+ added with this call (DO_ADD), or has been added in a previous call
+ (!DO_ADD).
+
+ The expected usage is as follows: Call _dl_add_to_slotinfo for
+ several link maps with DO_ADD set to false, and record if any calls
+ result in a true result. If there was a true result, call
+ _dl_add_to_slotinfo again, this time with DO_ADD set to true. (For
+ simplicity, it's possible to call the function for link maps where
+ the previous result was false.) The return value from the second
+ round of calls can be ignored. If there was true result initially,
+ call _dl_update_slotinfo to update the TLS generation counter. */
+bool
_dl_add_to_slotinfo (struct link_map *l, bool do_add)
{
+ if (l->l_tls_blocksize == 0 || l->l_tls_in_slotinfo)
+ return false;
+
/* Now that we know the object is loaded successfully add
modules containing TLS data to the dtv info table. We
might have to increase its size. */
@@ -1163,7 +1190,10 @@ cannot create TLS data structures"));
atomic_store_relaxed (&listp->slotinfo[idx].map, l);
atomic_store_relaxed (&listp->slotinfo[idx].gen,
GL(dl_tls_generation) + 1);
+ l->l_tls_in_slotinfo = true;
}
+
+ return true;
}
#if THREAD_GSCOPE_IN_TCB
diff -Nrup a/elf/tst-dlopen-tlsreinit1.c b/elf/tst-dlopen-tlsreinit1.c
--- a/elf/tst-dlopen-tlsreinit1.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinit1.c 2024-08-21 14:04:52.834912875 -0400
@@ -0,0 +1,40 @@
+/* Test that dlopen preserves already accessed TLS (bug 31717).
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdbool.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+#include <ctype.h>
+
+static int
+do_test (void)
+{
+ void *handle = xdlopen ("tst-dlopen-tlsreinitmod1.so", RTLD_NOW);
+
+ bool *tlsreinitmod3_tested = xdlsym (handle, "tlsreinitmod3_tested");
+ TEST_VERIFY (*tlsreinitmod3_tested);
+
+ xdlclose (handle);
+
+ /* This crashes if the libc.so.6 TLS image has been reverted. */
+ TEST_VERIFY (!isupper ('@'));
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff -Nrup a/elf/tst-dlopen-tlsreinit2.c b/elf/tst-dlopen-tlsreinit2.c
--- a/elf/tst-dlopen-tlsreinit2.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinit2.c 2024-08-21 14:04:52.834912875 -0400
@@ -0,0 +1,39 @@
+/* Test that dlopen preserves already accessed TLS (bug 31717).
+ Variant with initially-linked modules.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <ctype.h>
+#include <stdbool.h>
+#include <support/check.h>
+#include <support/xdlfcn.h>
+
+
+static int
+do_test (void)
+{
+ /* Defined in tst-dlopen-tlsreinitmod3.so. */
+ extern bool tlsreinitmod3_tested;
+ TEST_VERIFY (tlsreinitmod3_tested);
+
+ /* This crashes if the libc.so.6 TLS image has been reverted. */
+ TEST_VERIFY (!isupper ('@'));
+
+ return 0;
+}
+
+#include <support/test-driver.c>
diff -Nrup a/elf/tst-dlopen-tlsreinit3.c b/elf/tst-dlopen-tlsreinit3.c
--- a/elf/tst-dlopen-tlsreinit3.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinit3.c 2024-08-21 14:04:52.834912875 -0400
@@ -0,0 +1,2 @@
+/* Same code, but run with LD_AUDIT=tst-auditmod1.so. */
+#include "tst-dlopen-tlsreinit1.c"
diff -Nrup a/elf/tst-dlopen-tlsreinit4.c b/elf/tst-dlopen-tlsreinit4.c
--- a/elf/tst-dlopen-tlsreinit4.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinit4.c 2024-08-21 14:04:52.834912875 -0400
@@ -0,0 +1,2 @@
+/* Same code, but run with LD_AUDIT=tst-auditmod1.so. */
+#include "tst-dlopen-tlsreinit2.c"
diff -Nrup a/elf/tst-dlopen-tlsreinitmod1.c b/elf/tst-dlopen-tlsreinitmod1.c
--- a/elf/tst-dlopen-tlsreinitmod1.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinitmod1.c 2024-08-21 14:04:52.834912875 -0400
@@ -0,0 +1,20 @@
+/* Test that dlopen preserves already accessed TLS (bug 31717), module 1.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* This module triggers loading of tst-dlopen-tlsreinitmod2.so and
+ tst-dlopen-tlsreinitmod3.so. */
diff -Nrup a/elf/tst-dlopen-tlsreinitmod2.c b/elf/tst-dlopen-tlsreinitmod2.c
--- a/elf/tst-dlopen-tlsreinitmod2.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinitmod2.c 2024-08-21 14:04:52.835912880 -0400
@@ -0,0 +1,30 @@
+/* Test that dlopen preserves already accessed TLS (bug 31717), module 2.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+
+/* Defined in tst-dlopen-tlsreinitmod3.so. This an underlinked symbol
+ dependency. */
+extern void call_tlsreinitmod3 (void);
+
+static void __attribute__ ((constructor))
+tlsreinitmod2_init (void)
+{
+ puts ("info: constructor of tst-dlopen-tlsreinitmod2.so invoked");
+ call_tlsreinitmod3 ();
+}
diff -Nrup a/elf/tst-dlopen-tlsreinitmod3.c b/elf/tst-dlopen-tlsreinitmod3.c
--- a/elf/tst-dlopen-tlsreinitmod3.c 1969-12-31 19:00:00.000000000 -0500
+++ b/elf/tst-dlopen-tlsreinitmod3.c 2024-08-21 14:04:52.835912880 -0400
@@ -0,0 +1,102 @@
+/* Test that dlopen preserves already accessed TLS (bug 31717), module 3.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <dlfcn.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <unistd.h>
+
+/* Used to verify from the main program that the test ran. */
+bool tlsreinitmod3_tested;
+
+/* This TLS variable must not revert back to the initial state after
+ dlopen. */
+static __thread int tlsreinitmod3_state = 1;
+
+/* Set from the ELF constructor during dlopen. */
+static bool tlsreinitmod3_constructed;
+
+/* Second half of test, behind a compiler barrier. The compiler
+ barrier is necessary to prevent carrying over TLS address
+ information from call_tlsreinitmod3 to call_tlsreinitmod3_tail. */
+void call_tlsreinitmod3_tail (void *self) __attribute__ ((weak));
+
+/* Called from tst-dlopen-tlsreinitmod2.so. */
+void
+call_tlsreinitmod3 (void)
+{
+ printf ("info: call_tlsreinitmod3 invoked (state=%d)\n",
+ tlsreinitmod3_state);
+
+ if (tlsreinitmod3_constructed)
+ {
+ puts ("error: call_tlsreinitmod3 called after ELF constructor");
+ fflush (stdout);
+ /* Cannot rely on test harness due to dynamic linking. */
+ _exit (1);
+ }
+
+ tlsreinitmod3_state = 2;
+
+ /* Self-dlopen. This will run the ELF constructor. */
+ void *self = dlopen ("tst-dlopen-tlsreinitmod3.so", RTLD_NOW);
+ if (self == NULL)
+ {
+ printf ("error: dlopen: %s\n", dlerror ());
+ fflush (stdout);
+ /* Cannot rely on test harness due to dynamic linking. */
+ _exit (1);
+ }
+
+ call_tlsreinitmod3_tail (self);
+}
+
+void
+call_tlsreinitmod3_tail (void *self)
+{
+ printf ("info: dlopen returned in tlsreinitmod3 (state=%d)\n",
+ tlsreinitmod3_state);
+
+ if (!tlsreinitmod3_constructed)
+ {
+ puts ("error: dlopen did not call tlsreinitmod3 ELF constructor");
+ fflush (stdout);
+ /* Cannot rely on test harness due to dynamic linking. */
+ _exit (1);
+ }
+
+ if (tlsreinitmod3_state != 2)
+ {
+ puts ("error: TLS state reverted in tlsreinitmod3");
+ fflush (stdout);
+ /* Cannot rely on test harness due to dynamic linking. */
+ _exit (1);
+ }
+
+ dlclose (self);
+
+ /* Signal test completion to the main program. */
+ tlsreinitmod3_tested = true;
+}
+
+static void __attribute__ ((constructor))
+tlsreinitmod3_init (void)
+{
+ puts ("info: constructor of tst-dlopen-tlsreinitmod3.so invoked");
+ tlsreinitmod3_constructed = true;
+}
diff -Nrup a/include/link.h b/include/link.h
--- a/include/link.h 2024-08-21 14:24:24.556066841 -0400
+++ b/include/link.h 2024-08-21 14:23:54.674908823 -0400
@@ -211,6 +211,8 @@ struct link_map
freed, ie. not allocated with
the dummy malloc in ld.so. */
unsigned int l_ld_readonly:1; /* Nonzero if dynamic section is readonly. */
+ unsigned int l_tls_in_slotinfo:1; /* TLS slotinfo updated in dlopen. */
+
/* NODELETE status of the map. Only valid for maps of type
lt_loaded. Lazy binding sets l_nodelete_active directly,
diff -Nrup a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
--- a/sysdeps/generic/ldsodefs.h 2024-08-21 14:24:25.317070865 -0400
+++ b/sysdeps/generic/ldsodefs.h 2024-08-21 14:04:52.835912880 -0400
@@ -1291,13 +1291,7 @@ extern void *_dl_open (const char *name,
extern int _dl_scope_free (void *) attribute_hidden;
-/* Add module to slot information data. If DO_ADD is false, only the
- required memory is allocated. Must be called with GL
- (dl_load_tls_lock) acquired. If the function has already been called
- for the link map L with !do_add, then this function will not raise
- an exception, otherwise it is possible that it encounters a memory
- allocation failure. */
-extern void _dl_add_to_slotinfo (struct link_map *l, bool do_add)
+extern bool _dl_add_to_slotinfo (struct link_map *l, bool do_add)
attribute_hidden;
/* Update slot information data for at least the generation of the

@ -0,0 +1,16 @@
Author: Patsy Griffin <patsy@redhat.com>
Fix a typo in naming tst-dlopen-tlsreinit1.out
diff -Nrup a/elf/Makefile b/elf/Makefile
--- a/elf/Makefile 2024-08-16 13:27:00.700921146 -0400
+++ b/elf/Makefile 2024-08-16 13:29:12.951628406 -0400
@@ -2802,7 +2802,7 @@ $(objpfx)tst-dlopen-tlsreinit4: \
# tst-dlopen-tlsreinitmod3.so. The dependency is provided via
# $(objpfx)tst-dlopen-tlsreinitmod1.so.
tst-dlopen-tlsreinitmod2.so-no-z-defs = yes
-$(objpfx)tst-dlopen-tlsreinit.out: $(objpfx)tst-dlopen-tlsreinitmod1.so \
+$(objpfx)tst-dlopen-tlsreinit1.out: $(objpfx)tst-dlopen-tlsreinitmod1.so \
$(objpfx)tst-dlopen-tlsreinitmod2.so $(objpfx)tst-dlopen-tlsreinitmod3.so
# Reuse an audit module which provides ample debug logging.
$(objpfx)tst-dlopen-tlsreinit3.out: $(objpfx)tst-auditmod1.so

@ -155,7 +155,7 @@ end \
Summary: The GNU libc libraries
Name: glibc
Version: %{glibcversion}
Release: 100%{?dist}
Release: 100%{?dist}.4
# In general, GPLv2+ is used by programs, LGPLv2+ is used for
# libraries.
@ -808,6 +808,16 @@ Patch571: glibc-RHEL-16643-5.patch
Patch572: glibc-RHEL-16643-6.patch
Patch573: glibc-RHEL-19444.patch
Patch574: glibc-RHEL-21556.patch
Patch575: glibc-RHEL-32480.patch
Patch576: glibc-RHEL-34318-1.patch
Patch577: glibc-RHEL-34318-2.patch
Patch578: glibc-RHEL-34318-3.patch
Patch579: glibc-RHEL-34318-4.patch
Patch580: glibc-RHEL-39993-1.patch
Patch581: glibc-RHEL-39993-2.patch
Patch582: glibc-RHEL-46763-1.patch
Patch583: glibc-RHEL-46763-2.patch
Patch584: glibc-RHEL-46763-3.patch
##############################################################################
# Continued list of core "glibc" package information:
@ -2966,6 +2976,23 @@ update_gconv_modules_cache ()
%endif
%changelog
* Tue Aug 27 2024 Patsy Griffin <patsy@redhat.com> - 2.34-100.4
- elf: Clarify and invert second argument of _dl_allocate_tls_init
- elf: Avoid re-initializing already allocated TLS in dlopen (RHEL-46763)
* Fri Jul 12 2024 Patsy Griffin <patsy@redhat.com> - 2.34-100.3
- elf: Avoid some free (NULL) calls in _dl_update_slotinfo
- elf: Support recursive use of dynamic TLS in interposed malloc (RHEL-39993)
* Mon Apr 29 2024 Florian Weimer <fweimer@redhat.com> - 2.34-100.2
- CVE-2024-33599: nscd: buffer overflow in netgroup cache (RHEL-34318)
- CVE-2024-33600: nscd: null pointer dereferences in netgroup cache
- CVE-2024-33601: nscd: crash on out-of-memory condition
- CVE-2024-33602: nscd: memory corruption with NSS netgroup modules
* Tue Apr 16 2024 Florian Weimer <fweimer@redhat.com> - 2.34-100.1
- CVE-2024-2961: Out of bounds write in iconv conversion to ISO-2022-CN-EXT (RHEL-32480)
* Wed Jan 24 2024 Patsy Griffin <patsy@redhat.com> - 2.34-100
- manual: fix order of arguments of memalign and aligned_alloc (RHEL-21556)

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