SOURCES/RHEL-18169_h1-reject-special-char-URI-path-component.patch

@@ -0,0 +1,119 @@
+From e5a741f94977840c58775b38f8ed830207f7e4d0 Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Tue, 8 Aug 2023 16:17:22 +0200
+Subject: [PATCH] BUG/MINOR: h1: do not accept '#' as part of the URI component
+
+Seth Manesse and Paul Plasil reported that the "path" sample fetch
+function incorrectly accepts '#' as part of the path component. This
+can in some cases lead to misrouted requests for rules that would apply
+on the suffix:
+
+    use_backend static if { path_end .png .jpg .gif .css .js }
+
+Note that this behavior can be selectively configured using
+"normalize-uri fragment-encode" and "normalize-uri fragment-strip".
+
+The problem is that while the RFC says that this '#' must never be
+emitted, as often it doesn't suggest how servers should handle it. A
+diminishing number of servers still do accept it and trim it silently,
+while others are rejecting it, as indicated in the conversation below
+with other implementers:
+
+   https://lists.w3.org/Archives/Public/ietf-http-wg/2023JulSep/0070.html
+
+Looking at logs from publicly exposed servers, such requests appear at
+a rate of roughly 1 per million and only come from attacks or poorly
+written web crawlers incorrectly following links found on various pages.
+
+Thus it looks like the best solution to this problem is to simply reject
+such ambiguous requests by default, and include this in the list of
+controls that can be disabled using "option accept-invalid-http-request".
+
+We're already rejecting URIs containing any control char anyway, so we
+should also reject '#'.
+
+In the H1 parser for the H1_MSG_RQURI state, there is an accelerated
+parser for bytes 0x21..0x7e that has been tightened to 0x24..0x7e (it
+should not impact perf since 0x21..0x23 are not supposed to appear in
+a URI anyway). This way '#' falls through the fine-grained filter and
+we can add the special case for it also conditionned by a check on the
+proxy's option "accept-invalid-http-request", with no overhead for the
+vast majority of valid URIs. Here this information is available through
+h1m->err_pos that's set to -2 when the option is here (so we don't need
+to change the API to expose the proxy). Example with a trivial GET
+through netcat:
+
+  [08/Aug/2023:16:16:52.651] frontend layer1 (#2): invalid request
+    backend <NONE> (#-1), server <NONE> (#-1), event #0, src 127.0.0.1:50812
+    buffer starts at 0 (including 0 out), 16361 free,
+    len 23, wraps at 16336, error at position 7
+    H1 connection flags 0x00000000, H1 stream flags 0x00000810
+    H1 msg state MSG_RQURI(4), H1 msg flags 0x00001400
+    H1 chunk len 0 bytes, H1 body len 0 bytes :
+
+    00000  GET /aa#bb HTTP/1.0\r\n
+    00021  \r\n
+
+This should be progressively backported to all stable versions along with
+the following patch:
+
+    REGTESTS: http-rules: add accept-invalid-http-request for normalize-uri tests
+
+Similar fixes for h2 and h3 will come in followup patches.
+
+Thanks to Seth Manesse and Paul Plasil for reporting this problem with
+detailed explanations.
+
+(cherry picked from commit 2eab6d354322932cfec2ed54de261e4347eca9a6)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 9bf75c8e22a8f2537f27c557854a8803087046d0)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 9facd01c9ac85fe9bcb331594b80fa08e7406552)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 832b672eee54866c7a42a1d46078cc9ae0d544d9)
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ src/h1.c | 15 +++++++++++----
+ 1 file changed, 11 insertions(+), 4 deletions(-)
+
+diff --git a/src/h1.c b/src/h1.c
+index eeda311b7..91d3dc47a 100644
+--- a/src/h1.c
++++ b/src/h1.c
+@@ -480,13 +480,13 @@ int h1_headers_to_hdr_list(char *start, const char *stop,
+ 	case H1_MSG_RQURI:
+ 	http_msg_rquri:
+ #ifdef HA_UNALIGNED_LE
+-		/* speedup: skip bytes not between 0x21 and 0x7e inclusive */
++		/* speedup: skip bytes not between 0x24 and 0x7e inclusive */
+ 		while (ptr <= end - sizeof(int)) {
+-			int x = *(int *)ptr - 0x21212121;
++			int x = *(int *)ptr - 0x24242424;
+ 			if (x & 0x80808080)
+ 				break;
+ 
+-			x -= 0x5e5e5e5e;
++			x -= 0x5b5b5b5b;
+ 			if (!(x & 0x80808080))
+ 				break;
+ 
+@@ -498,8 +498,15 @@ int h1_headers_to_hdr_list(char *start, const char *stop,
+ 			goto http_msg_ood;
+ 		}
+ 	http_msg_rquri2:
+-		if (likely((unsigned char)(*ptr - 33) <= 93)) /* 33 to 126 included */
++		if (likely((unsigned char)(*ptr - 33) <= 93)) { /* 33 to 126 included */
++			if (*ptr == '#') {
++				if (h1m->err_pos < -1) /* PR_O2_REQBUG_OK not set */
++					goto invalid_char;
++				if (h1m->err_pos == -1) /* PR_O2_REQBUG_OK set: just log */
++					h1m->err_pos = ptr - start + skip;
++			}
+ 			EAT_AND_JUMP_OR_RETURN(ptr, end, http_msg_rquri2, http_msg_ood, state, H1_MSG_RQURI);
++		}
+ 
+ 		if (likely(HTTP_IS_SPHT(*ptr))) {
+ 			sl.rq.u.len = ptr - sl.rq.u.ptr;
+-- 
+2.43.0
+

SOURCES/RHEL-18169_h2-pass-accept-invalid-http-request-request-parser.patch

@@ -0,0 +1,76 @@
+From f86e994f5fb5851cd6e4f7f6b366e37765014b9f Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Tue, 8 Aug 2023 15:38:28 +0200
+Subject: [PATCH] MINOR: h2: pass accept-invalid-http-request down the request
+ parser
+
+We're adding a new argument "relaxed" to h2_make_htx_request() so that
+we can control its level of acceptance of certain invalid requests at
+the proxy level with "option accept-invalid-http-request". The goal
+will be to add deactivable checks that are still desirable to have by
+default. For now no test is subject to it.
+
+(cherry picked from commit d93a00861d714313faa0395ff9e2acb14b0a2fca)
+ [ad: backported for following fix : BUG/MINOR: h2: reject more chars
+  from the :path pseudo header]
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit b6be1a4f858eb6602490c192235114c1a163fef9)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 26fa3a285df0748fc79e73e552161268b66fb527)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 014945a1508f43e88ac4e89950fa9037e4fb0679)
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ include/haproxy/h2.h | 2 +-
+ src/h2.c             | 6 +++++-
+ src/mux_h2.c         | 3 ++-
+ 3 files changed, 8 insertions(+), 3 deletions(-)
+
+diff --git a/include/haproxy/h2.h b/include/haproxy/h2.h
+index 8d2aa9511..4f872b99d 100644
+--- a/include/haproxy/h2.h
++++ b/include/haproxy/h2.h
+@@ -207,7 +207,7 @@ extern struct h2_frame_definition h2_frame_definition[H2_FT_ENTRIES];
+ /* various protocol processing functions */
+ 
+ int h2_parse_cont_len_header(unsigned int *msgf, struct ist *value, unsigned long long *body_len);
+-int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len);
++int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, int relaxed);
+ int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, char *upgrade_protocol);
+ int h2_make_htx_trailers(struct http_hdr *list, struct htx *htx);
+ 
+diff --git a/src/h2.c b/src/h2.c
+index e1554642e..94c384111 100644
+--- a/src/h2.c
++++ b/src/h2.c
+@@ -399,8 +399,12 @@ static struct htx_sl *h2_prepare_htx_reqline(uint32_t fields, struct ist *phdr,
+  *
+  * The Cookie header will be reassembled at the end, and for this, the <list>
+  * will be used to create a linked list, so its contents may be destroyed.
++ *
++ * When <relaxed> is non-nul, some non-dangerous checks will be ignored. This
++ * is in order to satisfy "option accept-invalid-http-request" for
++ * interoperability purposes.
+  */
+-int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len)
++int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, int relaxed)
+ {
+ 	struct ist phdr_val[H2_PHDR_NUM_ENTRIES];
+ 	uint32_t fields; /* bit mask of H2_PHDR_FND_* */
+diff --git a/src/mux_h2.c b/src/mux_h2.c
+index 0ab86534c..61fd1a4d2 100644
+--- a/src/mux_h2.c
++++ b/src/mux_h2.c
+@@ -4917,7 +4917,8 @@ static int h2c_decode_headers(struct h2c *h2c, struct buffer *rxbuf, uint32_t *f
+ 	if (h2c->flags & H2_CF_IS_BACK)
+ 		outlen = h2_make_htx_response(list, htx, &msgf, body_len, upgrade_protocol);
+ 	else
+-		outlen = h2_make_htx_request(list, htx, &msgf, body_len);
++		outlen = h2_make_htx_request(list, htx, &msgf, body_len,
++					     !!(((const struct session *)h2c->conn->owner)->fe->options2 & PR_O2_REQBUG_OK));
+ 
+ 	if (outlen < 0 || htx_free_space(htx) < global.tune.maxrewrite) {
+ 		/* too large headers? this is a stream error only */
+-- 
+2.43.0
+

SOURCES/RHEL-18169_h2-reject-special-char-from-pseudo-path-header.patch

@@ -0,0 +1,71 @@
+From af232e47e6264122bed3681210b054ff38ec8de8 Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Tue, 8 Aug 2023 15:40:49 +0200
+Subject: [PATCH] BUG/MINOR: h2: reject more chars from the :path pseudo header
+
+This is the h2 version of this previous fix:
+
+    BUG/MINOR: h1: do not accept '#' as part of the URI component
+
+In addition to the current NUL/CR/LF, this will also reject all other
+control chars, the space and '#' from the :path pseudo-header, to avoid
+taking the '#' for a part of the path. It's still possible to fall back
+to the previous behavior using "option accept-invalid-http-request".
+
+This patch modifies the request parser to change the ":path" pseudo header
+validation function with a new one that rejects 0x00-0x1F (control chars),
+space and '#'. This way such chars will be dropped early in the chain, and
+the search for '#' doesn't incur a second pass over the header's value.
+
+This should be progressively backported to stable versions, along with the
+following commits it relies on:
+
+     REGTESTS: http-rules: add accept-invalid-http-request for normalize-uri tests
+     REORG: http: move has_forbidden_char() from h2.c to http.h
+     MINOR: ist: add new function ist_find_range() to find a character range
+     MINOR: http: add new function http_path_has_forbidden_char()
+     MINOR: h2: pass accept-invalid-http-request down the request parser
+
+(cherry picked from commit b3119d4fb4588087e2483a80b01d322683719e29)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 462a8600ce9e478573a957e046b446a7dcffd286)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 648e59e30723b8fd4e71aab02cb679f6ea7446e7)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit c8e07f2fd8b5462527f102f7145d6027c0d041da)
+[wt: minor ctx adjustments]
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ src/h2.c | 15 +++++++++++----
+ 1 file changed, 11 insertions(+), 4 deletions(-)
+
+diff --git a/src/h2.c b/src/h2.c
+index 94c384111..e190c52b5 100644
+--- a/src/h2.c
++++ b/src/h2.c
+@@ -440,11 +440,18 @@ int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *ms
+ 		}
+ 
+ 		/* RFC7540#10.3: intermediaries forwarding to HTTP/1 must take care of
+-		 * rejecting NUL, CR and LF characters.
++		 * rejecting NUL, CR and LF characters. For :path we reject all CTL
++		 * chars, spaces, and '#'.
+ 		 */
+-		ctl = ist_find_ctl(list[idx].v);
+-		if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
+-			goto fail;
++		if (phdr == H2_PHDR_IDX_PATH && !relaxed) {
++			ctl = ist_find_range(list[idx].v, 0, '#');
++			if (unlikely(ctl) && http_path_has_forbidden_char(list[idx].v, ctl))
++				goto fail;
++		} else {
++			ctl = ist_find_ctl(list[idx].v);
++			if (unlikely(ctl) && has_forbidden_char(list[idx].v, ctl))
++				goto fail;
++		}
+ 
+ 		if (phdr > 0 && phdr < H2_PHDR_NUM_ENTRIES) {
+ 			/* insert a pseudo header by its index (in phdr) and value (in value) */
+-- 
+2.43.0
+

SOURCES/RHEL-18169_http-add-new-function-http_path_has_forbidden_char.patch

@@ -0,0 +1,59 @@
+From 0f57ac20b046b70275192651d7b6c978032e6a36 Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Tue, 8 Aug 2023 15:24:54 +0200
+Subject: [PATCH] MINOR: http: add new function http_path_has_forbidden_char()
+
+As its name implies, this function checks if a path component has any
+forbidden headers starting at the designated location. The goal is to
+seek from the result of a successful ist_find_range() for more precise
+chars. Here we're focusing on 0x00-0x1F, 0x20 and 0x23 to make sure
+we're not too strict at this point.
+
+(cherry picked from commit 30f58f4217d585efeac3d85cb1b695ba53b7760b)
+ [ad: backported for following fix : BUG/MINOR: h2: reject more chars
+  from the :path pseudo header]
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit b491940181a88bb6c69ab2afc24b93a50adfa67c)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit f7666e5e43ce63e804ebffdf224d92cfd3367282)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit c699bb17b7e334c9d56e829422e29e5a204615ec)
+[wt: adj minor ctx in http.h]
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ include/haproxy/http.h | 19 +++++++++++++++++++
+ 1 file changed, 19 insertions(+)
+
+diff --git a/include/haproxy/http.h b/include/haproxy/http.h
+index 8a86cb6e9..e8c5b850f 100644
+--- a/include/haproxy/http.h
++++ b/include/haproxy/http.h
+@@ -134,6 +134,25 @@ static inline enum http_etag_type http_get_etag_type(const struct ist etag)
+ 	return ETAG_INVALID;
+ }
+ 
++/* Looks into <ist> for forbidden characters for :path values (0x00..0x1F,
++ * 0x20, 0x23), starting at pointer <start> which must be within <ist>.
++ * Returns non-zero if such a character is found, 0 otherwise. When run on
++ * unlikely header match, it's recommended to first check for the presence
++ * of control chars using ist_find_ctl().
++ */
++static inline int http_path_has_forbidden_char(const struct ist ist, const char *start)
++{
++	do {
++		if ((uint8_t)*start <= 0x23) {
++			if ((uint8_t)*start < 0x20)
++				return 1;
++			if ((1U << ((uint8_t)*start & 0x1F)) & ((1<<3) | (1<<0)))
++				return 1;
++		}
++		start++;
++	} while (start < istend(ist));
++	return 0;
++}
+ 
+ #endif /* _HAPROXY_HTTP_H */
+ 
+-- 
+2.43.0
+

SOURCES/RHEL-18169_ist-add-new-function-ist_find_range.patch

@@ -0,0 +1,86 @@
+From edcff741698c9519dc44f3aa13de421baad7ff43 Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Tue, 8 Aug 2023 15:23:19 +0200
+Subject: [PATCH] MINOR: ist: add new function ist_find_range() to find a
+ character range
+
+This looks up the character range <min>..<max> in the input string and
+returns a pointer to the first one found. It's essentially the equivalent
+of ist_find_ctl() in that it searches by 32 or 64 bits at once, but deals
+with a range.
+
+(cherry picked from commit 197668de975e495f0c0f0e4ff51b96203fa9842d)
+ [ad: backported for following fix : BUG/MINOR: h2: reject more chars
+ from the :path pseudo header]
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 451ac6628acc4b9eed3260501a49c60d4e4d4e55)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 3468f7f8e04c9c5ca5c985c7511e05e78fe1eded)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit b375df60341c7f7a4904c2d8041a09c66115c754)
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ include/import/ist.h | 47 ++++++++++++++++++++++++++++++++++++++++++++
+ 1 file changed, 47 insertions(+)
+
+diff --git a/include/import/ist.h b/include/import/ist.h
+index 539a27d26..31566b105 100644
+--- a/include/import/ist.h
++++ b/include/import/ist.h
+@@ -746,6 +746,53 @@ static inline const char *ist_find_ctl(const struct ist ist)
+ 	return NULL;
+ }
+ 
++/* Returns a pointer to the first character found <ist> that belongs to the
++ * range [min:max] inclusive, or NULL if none is present. The function is
++ * optimized for strings having no such chars by processing up to sizeof(long)
++ * bytes at once on architectures supporting efficient unaligned accesses.
++ * Despite this it is not very fast (~0.43 byte/cycle) and should mostly be
++ * used on low match probability when it can save a call to a much slower
++ * function. Will not work for characters 0x80 and above. It's optimized for
++ * min and max to be known at build time.
++ */
++static inline const char *ist_find_range(const struct ist ist, unsigned char min, unsigned char max)
++{
++	const union { unsigned long v; } __attribute__((packed)) *u;
++	const char *curr = (void *)ist.ptr - sizeof(long);
++	const char *last = curr + ist.len;
++	unsigned long l1, l2;
++
++	/* easier with an exclusive boundary */
++	max++;
++
++	do {
++		curr += sizeof(long);
++		if (curr > last)
++			break;
++		u = (void *)curr;
++		/* add 0x<min><min><min><min>..<min> then subtract
++		 * 0x<max><max><max><max>..<max> to the value to generate a
++		 * carry in the lower byte if the byte contains a lower value.
++		 * If we generate a bit 7 that was not there, it means the byte
++		 * was min..max.
++		 */
++		l2  = u->v;
++		l1  = ~l2 & ((~0UL / 255) * 0x80); /* 0x808080...80 */
++		l2 += (~0UL / 255) * min;          /* 0x<min><min>..<min> */
++		l2 -= (~0UL / 255) * max;          /* 0x<max><max>..<max> */
++	} while ((l1 & l2) == 0);
++
++	last += sizeof(long);
++	if (__builtin_expect(curr < last, 0)) {
++		do {
++			if ((unsigned char)(*curr - min) < (unsigned char)(max - min))
++				return curr;
++			curr++;
++		} while (curr < last);
++	}
++	return NULL;
++}
++
+ /* looks for first occurrence of character <chr> in string <ist> and returns
+  * the tail of the string starting with this character, or (ist.end,0) if not
+  * found.
+-- 
+2.43.0
+

SOURCES/RHEL-18169_regtest-add-accept-invalid-http-request.patch

@@ -0,0 +1,46 @@
+From c7492154ef07d6c08aa1eb52502697bbc3f42a69 Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Tue, 8 Aug 2023 19:52:45 +0200
+Subject: [PATCH] REGTESTS: http-rules: add accept-invalid-http-request for
+ normalize-uri tests
+
+We'll soon block the '#' by default so let's prepare the test to continue
+to work.
+
+(cherry picked from commit 069d0e221e58a46119d7c049bb07fa4bcb8d0075)
+ [ad: backported for following fix : BUG/MINOR: h2: reject more chars
+  from the :path pseudo header]
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 1660481fab69856a39ac44cf88b76cdbcc0ea954)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 90d0300cea6cda18a4e20369f4dc0b4c4783d6c9)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 65849396fd6f192d9f14e81702c6c3851e580345)
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ reg-tests/http-rules/normalize_uri.vtc | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/reg-tests/http-rules/normalize_uri.vtc b/reg-tests/http-rules/normalize_uri.vtc
+index 6a1dc31dc..56acf2cef 100644
+--- a/reg-tests/http-rules/normalize_uri.vtc
++++ b/reg-tests/http-rules/normalize_uri.vtc
+@@ -127,6 +127,7 @@ haproxy h1 -conf {
+ 
+     frontend fe_fragment_strip
+         bind "fd@${fe_fragment_strip}"
++        option accept-invalid-http-request
+ 
+         http-request set-var(txn.before) url
+         http-request normalize-uri fragment-strip
+@@ -139,6 +140,7 @@ haproxy h1 -conf {
+ 
+     frontend fe_fragment_encode
+         bind "fd@${fe_fragment_encode}"
++        option accept-invalid-http-request
+ 
+         http-request set-var(txn.before) url
+         http-request normalize-uri fragment-encode
+-- 
+2.43.0
+

SOURCES/RHEL-7736_http-reject-empty-content-length-header.patch

@@ -0,0 +1,275 @@
+From ba9afd2774c03e434165475b537d0462801f49bb Mon Sep 17 00:00:00 2001
+From: Willy Tarreau <w@1wt.eu>
+Date: Wed, 9 Aug 2023 08:32:48 +0200
+Subject: [PATCH] BUG/MAJOR: http: reject any empty content-length header value
+
+The content-length header parser has its dedicated function, in order
+to take extreme care about invalid, unparsable, or conflicting values.
+But there's a corner case in it, by which it stops comparing values
+when reaching the end of the header. This has for a side effect that
+an empty value or a value that ends with a comma does not deserve
+further analysis, and it acts as if the header was absent.
+
+While this is not necessarily a problem for the value ending with a
+comma as it will be cause a header folding and will disappear, it is a
+problem for the first isolated empty header because this one will not
+be recontructed when next ones are seen, and will be passed as-is to the
+backend server. A vulnerable HTTP/1 server hosted behind haproxy that
+would just use this first value as "0" and ignore the valid one would
+then not be protected by haproxy and could be attacked this way, taking
+the payload for an extra request.
+
+In field the risk depends on the server. Most commonly used servers
+already have safe content-length parsers, but users relying on haproxy
+to protect a known-vulnerable server might be at risk (and the risk of
+a bug even in a reputable server should never be dismissed).
+
+A configuration-based work-around consists in adding the following rule
+in the frontend, to explicitly reject requests featuring an empty
+content-length header that would have not be folded into an existing
+one:
+
+    http-request deny if { hdr_len(content-length) 0 }
+
+The real fix consists in adjusting the parser so that it always expects a
+value at the beginning of the header or after a comma. It will now reject
+requests and responses having empty values anywhere in the C-L header.
+
+This needs to be backported to all supported versions. Note that the
+modification was made to functions h1_parse_cont_len_header() and
+http_parse_cont_len_header(). Prior to 2.8 the latter was in
+h2_parse_cont_len_header(). One day the two should be refused but the
+former is also used by Lua.
+
+The HTTP messaging reg-tests were completed to test these cases.
+
+Thanks to Ben Kallus of Dartmouth College and Narf Industries for
+reporting this! (this is in GH #2237).
+
+(cherry picked from commit 6492f1f29d738457ea9f382aca54537f35f9d856)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit a32f99f6f991d123ea3e307bf8aa63220836d365)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit 65921ee12d88e9fb1fa9f6cd8198fd64b3a3f37f)
+Signed-off-by: Amaury Denoyelle <adenoyelle@haproxy.com>
+(cherry picked from commit d17c50010d591d1c070e1cb0567a06032d8869e9)
+[wt: applied to h2_parse_cont_len_header() in src/h2.c instead]
+Signed-off-by: Willy Tarreau <w@1wt.eu>
+---
+ reg-tests/http-messaging/h1_to_h1.vtc | 26 ++++++++++++
+ reg-tests/http-messaging/h2_to_h1.vtc | 60 +++++++++++++++++++++++++++
+ src/h1.c                              | 20 +++++++--
+ src/h2.c                              | 20 +++++++--
+ 4 files changed, 120 insertions(+), 6 deletions(-)
+
+diff --git a/reg-tests/http-messaging/h1_to_h1.vtc b/reg-tests/http-messaging/h1_to_h1.vtc
+index c7d00858e..603c03210 100644
+--- a/reg-tests/http-messaging/h1_to_h1.vtc
++++ b/reg-tests/http-messaging/h1_to_h1.vtc
+@@ -275,3 +275,29 @@ client c3h1 -connect ${h1_feh1_sock} {
+ 	# arrive here.
+ 	expect_close
+ } -run
++
++client c4h1 -connect ${h1_feh1_sock} {
++	# this request is invalid and advertises an invalid C-L ending with an
++        # empty value, which results in a stream error.
++	txreq \
++	  -req "GET" \
++	  -url "/test31.html" \
++          -hdr "content-length: 0," \
++          -hdr "connection: close"
++	rxresp
++	expect resp.status == 400
++	expect_close
++} -run
++
++client c5h1 -connect ${h1_feh1_sock} {
++	# this request is invalid and advertises an empty C-L, which results
++	# in a stream error.
++	txreq \
++	  -req "GET" \
++	  -url "/test41.html" \
++          -hdr "content-length:" \
++          -hdr "connection: close"
++	rxresp
++	expect resp.status == 400
++	expect_close
++} -run
+diff --git a/reg-tests/http-messaging/h2_to_h1.vtc b/reg-tests/http-messaging/h2_to_h1.vtc
+index 0d2b1e5f2..ec7a7c123 100644
+--- a/reg-tests/http-messaging/h2_to_h1.vtc
++++ b/reg-tests/http-messaging/h2_to_h1.vtc
+@@ -10,6 +10,8 @@ barrier b1 cond 2 -cyclic
+ barrier b2 cond 2 -cyclic
+ barrier b3 cond 2 -cyclic
+ barrier b4 cond 2 -cyclic
++barrier b5 cond 2 -cyclic
++barrier b6 cond 2 -cyclic
+ 
+ server s1 {
+ 	rxreq
+@@ -31,6 +33,12 @@ server s1 {
+ 
+ 	barrier b4 sync
+ 	# the next request is never received
++
++	barrier b5 sync
++	# the next request is never received
++
++	barrier b6 sync
++	# the next request is never received
+ } -repeat 2 -start
+ 
+ haproxy h1 -conf {
+@@ -121,6 +129,32 @@ client c1h2 -connect ${h1_feh2_sock} {
+ 		txdata -data "this is sent and ignored"
+ 		rxrst
+ 	} -run
++
++	# fifth request is invalid and advertises an invalid C-L ending with an
++        # empty value, which results in a stream error.
++	stream 9 {
++		barrier b5 sync
++		txreq \
++		  -req "GET" \
++		  -scheme "https" \
++		  -url "/test5.html" \
++		  -hdr "content-length" "0," \
++		  -nostrend
++		rxrst
++	} -run
++
++	# sixth request is invalid and advertises an empty C-L, which results
++	# in a stream error.
++	stream 11 {
++		barrier b6 sync
++		txreq \
++		  -req "GET" \
++		  -scheme "https" \
++		  -url "/test6.html" \
++		  -hdr "content-length" "" \
++		  -nostrend
++		rxrst
++	} -run
+ } -run
+ 
+ # HEAD requests : don't work well yet
+@@ -263,4 +297,30 @@ client c3h2 -connect ${h1_feh2_sock} {
+ 		txdata -data "this is sent and ignored"
+ 		rxrst
+ 	} -run
++
++	# fifth request is invalid and advertises invalid C-L ending with an
++        # empty value, which results in a stream error.
++	stream 9 {
++		barrier b5 sync
++		txreq \
++		  -req "POST" \
++		  -scheme "https" \
++		  -url "/test25.html" \
++		  -hdr "content-length" "0," \
++		  -nostrend
++		rxrst
++	} -run
++
++	# sixth request is invalid and advertises an empty C-L, which results
++	# in a stream error.
++	stream 11 {
++		barrier b6 sync
++		txreq \
++		  -req "POST" \
++		  -scheme "https" \
++		  -url "/test26.html" \
++		  -hdr "content-length" "" \
++		  -nostrend
++		rxrst
++	} -run
+ } -run
+diff --git a/src/h1.c b/src/h1.c
+index 73de48be0..eeda311b7 100644
+--- a/src/h1.c
++++ b/src/h1.c
+@@ -34,13 +34,20 @@ int h1_parse_cont_len_header(struct h1m *h1m, struct ist *value)
+ 	int not_first = !!(h1m->flags & H1_MF_CLEN);
+ 	struct ist word;
+ 
+-	word.ptr = value->ptr - 1; // -1 for next loop's pre-increment
++	word.ptr = value->ptr;
+ 	e = value->ptr + value->len;
+ 
+-	while (++word.ptr < e) {
++	while (1) {
++		if (word.ptr >= e) {
++			/* empty header or empty value */
++			goto fail;
++		}
++
+ 		/* skip leading delimiter and blanks */
+-		if (unlikely(HTTP_IS_LWS(*word.ptr)))
++		if (unlikely(HTTP_IS_LWS(*word.ptr))) {
++			word.ptr++;
+ 			continue;
++		}
+ 
+ 		/* digits only now */
+ 		for (cl = 0, n = word.ptr; n < e; n++) {
+@@ -79,6 +86,13 @@ int h1_parse_cont_len_header(struct h1m *h1m, struct ist *value)
+ 		h1m->flags |= H1_MF_CLEN;
+ 		h1m->curr_len = h1m->body_len = cl;
+ 		*value = word;
++
++		/* Now either n==e and we're done, or n points to the comma,
++		 * and we skip it and continue.
++		 */
++		if (n++ == e)
++			break;
++
+ 		word.ptr = n;
+ 	}
+ 	/* here we've reached the end with a single value or a series of
+diff --git a/src/h2.c b/src/h2.c
+index dd1f7d9b6..e1554642e 100644
+--- a/src/h2.c
++++ b/src/h2.c
+@@ -80,13 +80,20 @@ int h2_parse_cont_len_header(unsigned int *msgf, struct ist *value, unsigned lon
+ 	int not_first = !!(*msgf & H2_MSGF_BODY_CL);
+ 	struct ist word;
+ 
+-	word.ptr = value->ptr - 1; // -1 for next loop's pre-increment
++	word.ptr = value->ptr;
+ 	e = value->ptr + value->len;
+ 
+-	while (++word.ptr < e) {
++	while (1) {
++		if (word.ptr >= e) {
++			/* empty header or empty value */
++			goto fail;
++		}
++
+ 		/* skip leading delimiter and blanks */
+-		if (unlikely(HTTP_IS_LWS(*word.ptr)))
++		if (unlikely(HTTP_IS_LWS(*word.ptr))) {
++			word.ptr++;
+ 			continue;
++		}
+ 
+ 		/* digits only now */
+ 		for (cl = 0, n = word.ptr; n < e; n++) {
+@@ -125,6 +132,13 @@ int h2_parse_cont_len_header(unsigned int *msgf, struct ist *value, unsigned lon
+ 		*msgf |= H2_MSGF_BODY_CL;
+ 		*body_len = cl;
+ 		*value = word;
++
++		/* Now either n==e and we're done, or n points to the comma,
++		 * and we skip it and continue.
++		 */
++		if (n++ == e)
++			break;
++
+ 		word.ptr = n;
+ 	}
+ 	/* here we've reached the end with a single value or a series of
+-- 
+2.43.0
+

SPECS/haproxy.spec

@@ -8,7 +8,7 @@
 
 Name:           haproxy
 Version:        2.4.22
-Release:        1%{?dist}
+Release:        3%{?dist}
 Summary:        HAProxy reverse proxy for high availability environments
 
 License:        GPLv2+
@@ -22,6 +22,14 @@ Source4:        %{name}.sysconfig
 Source5:        %{name}.sysusers
 Source6:        halog.1
 
+Patch0:	RHEL-7736_http-reject-empty-content-length-header.patch
+Patch1: RHEL-18169_h1-reject-special-char-URI-path-component.patch
+Patch2: RHEL-18169_h2-pass-accept-invalid-http-request-request-parser.patch
+Patch3: RHEL-18169_h2-reject-special-char-from-pseudo-path-header.patch
+Patch4: RHEL-18169_http-add-new-function-http_path_has_forbidden_char.patch
+Patch5: RHEL-18169_ist-add-new-function-ist_find_range.patch
+Patch6: RHEL-18169_regtest-add-accept-invalid-http-request.patch
+
 BuildRequires:  gcc
 BuildRequires:  lua-devel
 BuildRequires:  pcre2-devel
@@ -50,6 +58,13 @@ availability environments. Indeed, it can:
 
 %prep
 %setup -q
+%patch -P0 -p1
+%patch -P1 -p1
+%patch -P2 -p1
+%patch -P3 -p1
+%patch -P4 -p1
+%patch -P5 -p1
+%patch -P6 -p1
 
 %build
 regparm_opts=
@@ -132,15 +147,18 @@ done
 %{_sysusersdir}/%{name}.conf
 
 %changelog
+* Tue Jan 23 2024 Ryan O'Hara <rohara@redhat.com> - 2.4.22-3
+- Reject "#" as part of URI path component (CVE-2023-45539, RHEL-18169)
+
+* Wed Jan 17 2024 Ryan O'Hara <rohara@redhat.com> - 2.4.22-2
+- Reject any empty content-length header value (CVE-2023-40225, RHEL-7736)
+
 * Tue Jun 06 2023 Ryan O'Hara <rohara@redhat.com> - 2.4.22-1
 - Update to 2.4.22 (#2196530)
 
 * Tue May 02 2023 Ryan O'Hara <rohara@redhat.com> - 2.4.17-7
 - Fix uninitizalized resevered bytes (CVE-2023-0836, #2180861)
 
-* Fri Apr 14 2023 MSVSphere Packaging Team <packager@msvsphere.ru> - 2.4.17-6
-- Rebuilt for MSVSphere 9.2 beta
-
 * Mon Feb 27 2023 Ryan O'Hara <rohara@redhat.com> - 2.4.17-6
 - Reject empty http header field names (CVE-2023-25725, #2169510)