crypto: af_alg - fix possible uninit-value in alg_bind()

syzbot reported : BUG: KMSAN: uninit-value in alg_bind+0xe3/0xd90 crypto/af_alg.c:162 We need to check addr_len before dereferencing sa (or uaddr) Fixes: bb30b88 ("crypto: af_alg - whitelist mask and type") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: syzbot <[email protected]> Cc: Stephan Mueller <[email protected]> Cc: Herbert Xu <[email protected]> Signed-off-by: David S. Miller <[email protected]>
penberg · Apr 8, 2018 · a466856 · a466856
1 parent f12c643
commit a466856
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/crypto/af_alg.c b/crypto/af_alg.c
@@ -158,16 +158,16 @@ static int alg_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	void *private;
 	int err;
 
-	/* If caller uses non-allowed flag, return error. */
-	if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
-		return -EINVAL;
-
 	if (sock->state == SS_CONNECTED)
 		return -EINVAL;
 
 	if (addr_len < sizeof(*sa))
 		return -EINVAL;
 
+	/* If caller uses non-allowed flag, return error. */
+	if ((sa->salg_feat & ~allowed) || (sa->salg_mask & ~allowed))
+		return -EINVAL;
+
 	sa->salg_type[sizeof(sa->salg_type) - 1] = 0;
 	sa->salg_name[sizeof(sa->salg_name) + addr_len - sizeof(*sa) - 1] = 0;