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authorArchie Pusaka <apusaka@chromium.org>2021-03-23 16:32:20 +0800
committerMarcel Holtmann <marcel@holtmann.org>2021-03-23 16:03:48 +0100
commit3af70b39fa2d415dc86c370e5b24ddb9fdacbd6f (patch)
tree13712770eba5f02cb41b0751215e1a2e778c071d
parent8ff0278d106753a553d6cb2cf49a8888425b8187 (diff)
Bluetooth: check for zapped sk before connecting
There is a possibility of receiving a zapped sock on l2cap_sock_connect(). This could lead to interesting crashes, one such case is tearing down an already tore l2cap_sock as is happened with this call trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0xc4/0x118 lib/dump_stack.c:56 register_lock_class kernel/locking/lockdep.c:792 [inline] register_lock_class+0x239/0x6f6 kernel/locking/lockdep.c:742 __lock_acquire+0x209/0x1e27 kernel/locking/lockdep.c:3105 lock_acquire+0x29c/0x2fb kernel/locking/lockdep.c:3599 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:137 [inline] _raw_spin_lock_bh+0x38/0x47 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:307 [inline] lock_sock_nested+0x44/0xfa net/core/sock.c:2518 l2cap_sock_teardown_cb+0x88/0x2fb net/bluetooth/l2cap_sock.c:1345 l2cap_chan_del+0xa3/0x383 net/bluetooth/l2cap_core.c:598 l2cap_chan_close+0x537/0x5dd net/bluetooth/l2cap_core.c:756 l2cap_chan_timeout+0x104/0x17e net/bluetooth/l2cap_core.c:429 process_one_work+0x7e3/0xcb0 kernel/workqueue.c:2064 worker_thread+0x5a5/0x773 kernel/workqueue.c:2196 kthread+0x291/0x2a6 kernel/kthread.c:211 ret_from_fork+0x4e/0x80 arch/x86/entry/entry_64.S:604 Signed-off-by: Archie Pusaka <apusaka@chromium.org> Reported-by: syzbot+abfc0f5e668d4099af73@syzkaller.appspotmail.com Reviewed-by: Alain Michaud <alainm@chromium.org> Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Reviewed-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
-rw-r--r--net/bluetooth/l2cap_sock.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index f1b1edd0b697..c99d65ef13b1 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -179,9 +179,17 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr,
struct l2cap_chan *chan = l2cap_pi(sk)->chan;
struct sockaddr_l2 la;
int len, err = 0;
+ bool zapped;
BT_DBG("sk %p", sk);
+ lock_sock(sk);
+ zapped = sock_flag(sk, SOCK_ZAPPED);
+ release_sock(sk);
+
+ if (zapped)
+ return -EINVAL;
+
if (!addr || alen < offsetofend(struct sockaddr, sa_family) ||
addr->sa_family != AF_BLUETOOTH)
return -EINVAL;