ioctl(ATMARP_MKIP) allocates struct clip_vcc and set it to
vcc->user_back.
The code assumes that vcc_destroy_socket() passes NULL skb
to vcc->push() when the socket is close()d, and then clip_push()
frees clip_vcc.
However, ioctl(ATMARPD_CTRL) sets NULL to vcc->push() in
atm_init_atmarp(), resulting in memory leak.
Let's serialise two ioctl() by lock_sock() and check vcc->push()
in atm_init_atmarp() to prevent memleak.
Fixes:
1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250704062416.1613927-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
static int atm_init_atmarp(struct atm_vcc *vcc)
{
+ if (vcc->push == clip_push)
+ return -EINVAL;
+
mutex_lock(&atmarpd_lock);
if (atmarpd) {
mutex_unlock(&atmarpd_lock);
static int clip_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
struct atm_vcc *vcc = ATM_SD(sock);
+ struct sock *sk = sock->sk;
int err = 0;
switch (cmd) {
err = clip_create(arg);
break;
case ATMARPD_CTRL:
+ lock_sock(sk);
err = atm_init_atmarp(vcc);
if (!err) {
sock->state = SS_CONNECTED;
__module_get(THIS_MODULE);
}
+ release_sock(sk);
break;
case ATMARP_MKIP:
+ lock_sock(sk);
err = clip_mkip(vcc, arg);
+ release_sock(sk);
break;
case ATMARP_SETENTRY:
err = clip_setentry(vcc, (__force __be32)arg);