You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
203 lines
9.4 KiB
203 lines
9.4 KiB
From 58aba81d1e530d53e462ec4ae542570cd537264a Mon Sep 17 00:00:00 2001
|
|
From: Yu Watanabe <watanabe.yu+github@gmail.com>
|
|
Date: Wed, 22 Mar 2023 08:49:49 +0900
|
|
Subject: [PATCH] coredump: use unaligned_read_ne{32,64}() to parse auxv
|
|
|
|
Fixes a bug introduced by 3e4d0f6cf99f8677edd6a237382a65bfe758de03.
|
|
|
|
The auxv metadata is unaligned, as the length of the prefix
|
|
"COREDUMP_PROC_AUXV=" is 19. Hence, parse_auxv{32,64}() may triger
|
|
an undefined behavior (or at least cause slow down), which can be
|
|
detected when running on an undefined behavior sanitizer.
|
|
|
|
This also introduces a macro to define `parse_auxv{32,64}()`.
|
|
|
|
Fixes #26912.
|
|
|
|
(cherry picked from commit 9b032f932c4172fac379234d9d42cf2b266ccaea)
|
|
|
|
Related: #2170883
|
|
---
|
|
src/coredump/coredump.c | 149 ++++++++++++++++------------------------
|
|
1 file changed, 60 insertions(+), 89 deletions(-)
|
|
|
|
diff --git a/src/coredump/coredump.c b/src/coredump/coredump.c
|
|
index ea3d8c415a..b9c5f3ad04 100644
|
|
--- a/src/coredump/coredump.c
|
|
+++ b/src/coredump/coredump.c
|
|
@@ -48,6 +48,7 @@
|
|
#include "sync-util.h"
|
|
#include "tmpfile-util.h"
|
|
#include "uid-alloc-range.h"
|
|
+#include "unaligned.h"
|
|
#include "user-util.h"
|
|
|
|
/* The maximum size up to which we process coredumps. We use 1G on 32bit systems, and 32G on 64bit systems */
|
|
@@ -339,95 +340,65 @@ static int make_filename(const Context *context, char **ret) {
|
|
return 0;
|
|
}
|
|
|
|
-static int parse_auxv64(
|
|
- const uint64_t *auxv,
|
|
- size_t size_bytes,
|
|
- int *at_secure,
|
|
- uid_t *uid,
|
|
- uid_t *euid,
|
|
- gid_t *gid,
|
|
- gid_t *egid) {
|
|
-
|
|
- assert(auxv || size_bytes == 0);
|
|
-
|
|
- if (size_bytes % (2 * sizeof(uint64_t)) != 0)
|
|
- return log_warning_errno(SYNTHETIC_ERRNO(EIO), "Incomplete auxv structure (%zu bytes).", size_bytes);
|
|
-
|
|
- size_t words = size_bytes / sizeof(uint64_t);
|
|
-
|
|
- /* Note that we set output variables even on error. */
|
|
-
|
|
- for (size_t i = 0; i + 1 < words; i += 2)
|
|
- switch (auxv[i]) {
|
|
- case AT_SECURE:
|
|
- *at_secure = auxv[i + 1] != 0;
|
|
- break;
|
|
- case AT_UID:
|
|
- *uid = auxv[i + 1];
|
|
- break;
|
|
- case AT_EUID:
|
|
- *euid = auxv[i + 1];
|
|
- break;
|
|
- case AT_GID:
|
|
- *gid = auxv[i + 1];
|
|
- break;
|
|
- case AT_EGID:
|
|
- *egid = auxv[i + 1];
|
|
- break;
|
|
- case AT_NULL:
|
|
- if (auxv[i + 1] != 0)
|
|
- goto error;
|
|
- return 0;
|
|
- }
|
|
- error:
|
|
- return log_warning_errno(SYNTHETIC_ERRNO(ENODATA),
|
|
- "AT_NULL terminator not found, cannot parse auxv structure.");
|
|
-}
|
|
-
|
|
-static int parse_auxv32(
|
|
- const uint32_t *auxv,
|
|
- size_t size_bytes,
|
|
- int *at_secure,
|
|
- uid_t *uid,
|
|
- uid_t *euid,
|
|
- gid_t *gid,
|
|
- gid_t *egid) {
|
|
-
|
|
- assert(auxv || size_bytes == 0);
|
|
-
|
|
- size_t words = size_bytes / sizeof(uint32_t);
|
|
-
|
|
- if (size_bytes % (2 * sizeof(uint32_t)) != 0)
|
|
- return log_warning_errno(SYNTHETIC_ERRNO(EIO), "Incomplete auxv structure (%zu bytes).", size_bytes);
|
|
+#define _DEFINE_PARSE_AUXV(size, type, unaligned_read) \
|
|
+ static int parse_auxv##size( \
|
|
+ const void *auxv, \
|
|
+ size_t size_bytes, \
|
|
+ int *at_secure, \
|
|
+ uid_t *uid, \
|
|
+ uid_t *euid, \
|
|
+ gid_t *gid, \
|
|
+ gid_t *egid) { \
|
|
+ \
|
|
+ assert(auxv || size_bytes == 0); \
|
|
+ \
|
|
+ if (size_bytes % (2 * sizeof(type)) != 0) \
|
|
+ return log_warning_errno(SYNTHETIC_ERRNO(EIO), \
|
|
+ "Incomplete auxv structure (%zu bytes).", \
|
|
+ size_bytes); \
|
|
+ \
|
|
+ size_t words = size_bytes / sizeof(type); \
|
|
+ \
|
|
+ /* Note that we set output variables even on error. */ \
|
|
+ \
|
|
+ for (size_t i = 0; i + 1 < words; i += 2) { \
|
|
+ type key, val; \
|
|
+ \
|
|
+ key = unaligned_read((uint8_t*) auxv + i * sizeof(type)); \
|
|
+ val = unaligned_read((uint8_t*) auxv + (i + 1) * sizeof(type)); \
|
|
+ \
|
|
+ switch (key) { \
|
|
+ case AT_SECURE: \
|
|
+ *at_secure = val != 0; \
|
|
+ break; \
|
|
+ case AT_UID: \
|
|
+ *uid = val; \
|
|
+ break; \
|
|
+ case AT_EUID: \
|
|
+ *euid = val; \
|
|
+ break; \
|
|
+ case AT_GID: \
|
|
+ *gid = val; \
|
|
+ break; \
|
|
+ case AT_EGID: \
|
|
+ *egid = val; \
|
|
+ break; \
|
|
+ case AT_NULL: \
|
|
+ if (val != 0) \
|
|
+ goto error; \
|
|
+ return 0; \
|
|
+ } \
|
|
+ } \
|
|
+ error: \
|
|
+ return log_warning_errno(SYNTHETIC_ERRNO(ENODATA), \
|
|
+ "AT_NULL terminator not found, cannot parse auxv structure."); \
|
|
+ }
|
|
|
|
- /* Note that we set output variables even on error. */
|
|
+#define DEFINE_PARSE_AUXV(size)\
|
|
+ _DEFINE_PARSE_AUXV(size, uint##size##_t, unaligned_read_ne##size)
|
|
|
|
- for (size_t i = 0; i + 1 < words; i += 2)
|
|
- switch (auxv[i]) {
|
|
- case AT_SECURE:
|
|
- *at_secure = auxv[i + 1] != 0;
|
|
- break;
|
|
- case AT_UID:
|
|
- *uid = auxv[i + 1];
|
|
- break;
|
|
- case AT_EUID:
|
|
- *euid = auxv[i + 1];
|
|
- break;
|
|
- case AT_GID:
|
|
- *gid = auxv[i + 1];
|
|
- break;
|
|
- case AT_EGID:
|
|
- *egid = auxv[i + 1];
|
|
- break;
|
|
- case AT_NULL:
|
|
- if (auxv[i + 1] != 0)
|
|
- goto error;
|
|
- return 0;
|
|
- }
|
|
- error:
|
|
- return log_warning_errno(SYNTHETIC_ERRNO(ENODATA),
|
|
- "AT_NULL terminator not found, cannot parse auxv structure.");
|
|
-}
|
|
+DEFINE_PARSE_AUXV(32);
|
|
+DEFINE_PARSE_AUXV(64);
|
|
|
|
static int grant_user_access(int core_fd, const Context *context) {
|
|
int at_secure = -1;
|
|
@@ -464,11 +435,11 @@ static int grant_user_access(int core_fd, const Context *context) {
|
|
"Core file has non-native endianness, not adjusting permissions.");
|
|
|
|
if (elf[EI_CLASS] == ELFCLASS64)
|
|
- r = parse_auxv64((const uint64_t*) context->meta[META_PROC_AUXV],
|
|
+ r = parse_auxv64(context->meta[META_PROC_AUXV],
|
|
context->meta_size[META_PROC_AUXV],
|
|
&at_secure, &uid, &euid, &gid, &egid);
|
|
else
|
|
- r = parse_auxv32((const uint32_t*) context->meta[META_PROC_AUXV],
|
|
+ r = parse_auxv32(context->meta[META_PROC_AUXV],
|
|
context->meta_size[META_PROC_AUXV],
|
|
&at_secure, &uid, &euid, &gid, &egid);
|
|
if (r < 0)
|