4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet <edumazet@xxxxxxxxxx> 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@xxxxxxxxxx> Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Cc: Stephan Mueller <smueller@xxxxxxxxxx> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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;