@@ -817,20 +817,25 @@ static void __vsock_release(struct sock *sk, int level)
vsk = vsock_sk(sk);
pending = NULL; /* Compiler warning. */
- /* When "level" is SINGLE_DEPTH_NESTING, use the nested
- * version to avoid the warning "possible recursive locking
- * detected". When "level" is 0, lock_sock_nested(sk, level)
- * is the same as lock_sock(sk).
+ /* When "level" is SINGLE_DEPTH_NESTING, use the nested version to avoid
+ * the warning "possible recursive locking detected". When "level" is 0,
+ * lock_sock_nested(sk, level) is the same as lock_sock(sk).
*/
lock_sock_nested(sk, level);
- sock_orphan(sk);
+ /* Indicate to vsock_remove_sock() that the socket is being released and
+ * can be removed from the bound_table. Unlike transport reassignment
+ * case, where the socket must remain bound despite vsock_remove_sock()
+ * being called from the transport release() callback.
+ */
+ sock_set_flag(sk, SOCK_DEAD);
if (vsk->transport)
vsk->transport->release(vsk);
else if (sock_type_connectible(sk->sk_type))
vsock_remove_sock(vsk);
+ sock_orphan(sk);
sk->sk_shutdown = SHUTDOWN_MASK;
skb_queue_purge(&sk->sk_receive_queue);
During socket release, sock_orphan() is called without considering that it sets sk->sk_wq to NULL. Later, if SO_LINGER is enabled, this leads to a null pointer dereferenced in virtio_transport_wait_close(). Orphan the socket only after transport release. While there, reflow the other comment. Partially reverts the 'Fixes:' commit. KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f] lock_acquire+0x19e/0x500 _raw_spin_lock_irqsave+0x47/0x70 add_wait_queue+0x46/0x230 virtio_transport_release+0x4e7/0x7f0 __vsock_release+0xfd/0x490 vsock_release+0x90/0x120 __sock_release+0xa3/0x250 sock_close+0x14/0x20 __fput+0x35e/0xa90 __x64_sys_close+0x78/0xd0 do_syscall_64+0x93/0x1b0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Reported-by: syzbot+9d55b199192a4be7d02c@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9d55b199192a4be7d02c Fixes: fcdd2242c023 ("vsock: Keep the binding until socket destruction") Tested-by: Luigi Leonardi <leonardi@redhat.com> Signed-off-by: Michal Luczaj <mhal@rbox.co> --- net/vmw_vsock/af_vsock.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)