6.16-stable review patch. If anyone has any objections, please let me know.
------------------
From: Herbert Xu herbert@gondor.apana.org.au
[ Upstream commit 9574b2330dbd2b5459b74d3b5e9619d39299fc6f ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- crypto/af_alg.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/crypto/af_alg.c b/crypto/af_alg.c index f02c5586a8ab3..ca6fdcc6c54ac 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -1025,6 +1025,8 @@ 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) @@ -1064,7 +1066,6 @@ int af_alg_sendmsg(struct socket *sock, struct msghdr *msg, size_t size, ctx->used += plen; copied += plen; size -= plen; - ctx->merge = 0; } else { do { struct page *pg;