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: bb30b8848c ("crypto: af_alg - whitelist mask and type")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2018-04-07 13:42:36 -07:00 committed by David S. Miller
parent f12c643209
commit a466856e0b

View File

@ -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;