af_unix: Add sockaddr length checks before accessing sa_family in bind and connect handlers

Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in bind() and connect()
handlers of the AF_UNIX socket. Since neither syscall enforces a minimum
size of the corresponding memory region, very short sockaddrs (zero or
one byte long) result in operating on uninitialized memory while
referencing .sa_family.

Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mateusz Jurczyk 2017-06-08 11:13:36 +02:00 committed by David S. Miller
parent fc5b775da4
commit defbcf2dec

View file

@ -999,7 +999,8 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
struct path path = { };
err = -EINVAL;
if (sunaddr->sun_family != AF_UNIX)
if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
sunaddr->sun_family != AF_UNIX)
goto out;
if (addr_len == sizeof(short)) {
@ -1110,6 +1111,10 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
unsigned int hash;
int err;
err = -EINVAL;
if (alen < offsetofend(struct sockaddr, sa_family))
goto out;
if (addr->sa_family != AF_UNSPEC) {
err = unix_mkname(sunaddr, alen, &hash);
if (err < 0)