From: Herbert Xu <herbert@gondor.apana.org.au> mainline inclusion from mainline-v6.17-rc7 commit 9574b2330dbd2b5459b74d3b5e9619d39299fc6f category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/8202 CVE: CVE-2025-39931 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- If an error causes af_alg_sendmsg to abort, ctx->merge may contain a garbage value from the previous loop. This may then trigger a crash on the next entry into af_alg_sendmsg when it attempts to do a merge that can't be done. Fix this by setting ctx->merge to zero near the start of the loop. Fixes: 8ff590903d5 ("crypto: algif_skcipher - User-space interface for skcipher operations") Reported-by: Muhammad Alifa Ramdhan <ramdhan@starlabs.sg> Reported-by: Bing-Jhong Billy Jheng <billy@starlabs.sg> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Conflicts: crypto/af_alg.c [Context conflicts due to commit d3dccb0a487d ("crypto: af_alg - Fix merging of written data into spliced pages") not merge.] Signed-off-by: Gu Bowen <gubowen5@huawei.com> --- crypto/af_alg.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index 755e6caf18d2..99085c6b9656 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -911,6 +911,8 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, continue; } + ctx->merge = 0; + if (!af_alg_writable(sk)) { err = af_alg_wait_for_wmem(sk, msg->msg_flags); if (err) -- 2.43.0