4.9-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit a466856e0b7ab269cdf9461886d007e88ff575b0 upstream.
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: bb30b8848c85 ("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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- crypto/af_alg.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -157,16 +157,16 @@ static int alg_bind(struct socket *sock, 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) - 1] = 0;