6.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> commit 24c890dd712f6345e382256cae8c97abb0406b70 upstream. When a zero-length message is hashed by algif_hash, and an error is triggered, it tries to free an SG list that was never allocated in the first place. Fix this by not freeing the SG list on the zero-length error path. Reported-by: Shigeru Yoshida <syoshida@xxxxxxxxxx> Reported-by: xingwei lee <xrivendell7@xxxxxxxxx> Fixes: b6d972f68983 ("crypto: af_alg/hash: Fix recvmsg() after sendmsg(MSG_MORE)") Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Reported-by: syzbot+3266db0c26d1fbbe3abb@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- crypto/algif_hash.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/crypto/algif_hash.c +++ b/crypto/algif_hash.c @@ -91,13 +91,13 @@ static int hash_sendmsg(struct socket *s if (!(msg->msg_flags & MSG_MORE)) { err = hash_alloc_result(sk, ctx); if (err) - goto unlock_free; + goto unlock_free_result; ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0); err = crypto_wait_req(crypto_ahash_final(&ctx->req), &ctx->wait); if (err) - goto unlock_free; + goto unlock_free_result; } goto done_more; } @@ -170,6 +170,7 @@ unlock: unlock_free: af_alg_free_sg(&ctx->sgl); +unlock_free_result: hash_free_result(sk, ctx); ctx->more = false; goto unlock;