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

[ Upstream commit defbcf2dec ]

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 <>
Signed-off-by: David S. Miller <>
Signed-off-by: Greg Kroah-Hartman <>
Mateusz Jurczyk 6 years ago committed by Greg Kroah-Hartman
parent 386ed38f0f
commit bb84290cd2

@ -998,7 +998,8 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
struct path path = { NULL, NULL };
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)) {
@ -1109,6 +1110,10 @@ 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)