memcached: patch CVE-2023-46853

Details: https://nvd.nist.gov/vuln/detail/CVE-2023-46853

Backport the patch that is referenced by the NVD advisory.

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
This commit is contained in:
Gyorgy Sarvari 2026-03-04 12:39:55 +01:00
parent 5307edaa60
commit bd5d3494e4
2 changed files with 115 additions and 0 deletions

View File

@ -0,0 +1,114 @@
From 788c8ba8fe07d0df3c425458b6e3a1590cc25401 Mon Sep 17 00:00:00 2001
From: dormando <dormando@rydia.net>
Date: Wed, 2 Aug 2023 15:45:56 -0700
Subject: [PATCH] proxy: fix off-by-one if \r is missing
A bunch of the parser assumed we only had \r\n, but I didn't actually
have that strictness set. Some commands worked and some broke in subtle
ways when just "\n" was being submitted.
I'm not 100% confident in this change yet so I'm opening a PR to stage
it while I run some more thorough tests.
CVE: CVE-2023-46853
Upstream-Status: Backport [https://github.com/memcached/memcached/commit/6987918e9a3094ec4fc8976f01f769f624d790fa]
Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
---
proxy.h | 1 +
proxy_request.c | 22 ++++++++++++++++------
t/proxy.t | 5 +++--
3 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/proxy.h b/proxy.h
index 86b4aa9..df9ebd6 100644
--- a/proxy.h
+++ b/proxy.h
@@ -268,6 +268,7 @@ struct mcp_parser_s {
uint8_t keytoken; // because GAT. sigh. also cmds without a key.
uint32_t parsed; // how far into the request we parsed already
uint32_t reqlen; // full length of request buffer.
+ uint32_t endlen; // index to the start of \r\n or \n
int vlen;
uint32_t klen; // length of key.
uint16_t tokens[PARSER_MAX_TOKENS]; // offsets for start of each token
diff --git a/proxy_request.c b/proxy_request.c
index f351cc1..1c34182 100644
--- a/proxy_request.c
+++ b/proxy_request.c
@@ -9,7 +9,7 @@
// where we later scan or directly feed data into API's.
static int _process_tokenize(mcp_parser_t *pr, const size_t max) {
const char *s = pr->request;
- int len = pr->reqlen - 2;
+ int len = pr->endlen;
// since multigets can be huge, we can't purely judge reqlen against this
// limit, but we also can't index past it since the tokens are shorts.
@@ -79,7 +79,7 @@ static int _process_request_key(mcp_parser_t *pr) {
// Returns the offset for the next key.
size_t _process_request_next_key(mcp_parser_t *pr) {
const char *cur = pr->request + pr->parsed;
- int remain = pr->reqlen - pr->parsed - 2;
+ int remain = pr->endlen - pr->parsed;
// chew off any leading whitespace.
while (remain) {
@@ -112,7 +112,7 @@ static int _process_request_metaflags(mcp_parser_t *pr, int token) {
return 0;
}
const char *cur = pr->request + pr->tokens[token];
- const char *end = pr->request + pr->reqlen - 2;
+ const char *end = pr->request + pr->endlen;
// We blindly convert flags into bits, since the range of possible
// flags is deliberately < 64.
@@ -276,15 +276,25 @@ int process_request(mcp_parser_t *pr, const char *command, size_t cmdlen) {
return -1;
}
- const char *s = memchr(command, ' ', cmdlen-2);
+ // Commands can end with bare '\n's. Depressingly I intended to be strict
+ // with a \r\n requirement but never did this and need backcompat.
+ // In this case we _know_ \n is at cmdlen because we can't enter this
+ // function otherwise.
+ if (cm[cmdlen-2] == '\r') {
+ pr->endlen = cmdlen - 2;
+ } else {
+ pr->endlen = cmdlen - 1;
+ }
+
+ const char *s = memchr(command, ' ', pr->endlen);
if (s != NULL) {
cl = s - command;
} else {
- cl = cmdlen - 2;
+ cl = pr->endlen;
}
pr->keytoken = 0;
pr->has_space = false;
- pr->parsed = cl + 1;
+ pr->parsed = cl;
pr->request = command;
pr->reqlen = cmdlen;
int token_max = PARSER_MAX_TOKENS;
diff --git a/t/proxy.t b/t/proxy.t
index c85796d..203924b 100644
--- a/t/proxy.t
+++ b/t/proxy.t
@@ -151,13 +151,14 @@ my $p_sock = $p_srv->sock;
# NOTE: memcached always allowed [\r]\n for single command lines, but payloads
# (set/etc) require exactly \r\n as termination.
# doc/protocol.txt has always specified \r\n for command/response.
-# Proxy is more strict than normal server in this case.
+# Note a bug lead me to believe that the proxy was more strict, we accept any
+# \n or \r\n terminated commands.
{
my $s = $srv[0]->sock;
print $s "version\n";
like(<$s>, qr/VERSION/, "direct server version cmd with just newline");
print $p_sock "version\n";
- like(<$p_sock>, qr/SERVER_ERROR/, "proxy version cmd with just newline");
+ like(<$p_sock>, qr/VERSION/, "proxy version cmd with just newline");
print $p_sock "version\r\n";
like(<$p_sock>, qr/VERSION/, "proxy version cmd with full CRLF");
}

View File

@ -22,6 +22,7 @@ RDEPENDS:${PN} += "perl perl-module-posix perl-module-autoloader \
SRC_URI = "http://www.memcached.org/files/${BP}.tar.gz \
file://memcached-add-hugetlbfs-check.patch \
file://CVE-2023-46852.patch \
file://CVE-2023-46853.patch \
"
SRC_URI[sha256sum] = "8d7abe3d649378edbba16f42ef1d66ca3f2ac075f2eb97145ce164388e6ed515"