Hi Archie, > 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@xxxxxxxxxxxx> > Reported-by: syzbot+abfc0f5e668d4099af73@xxxxxxxxxxxxxxxxxxxxxxxxx > Reviewed-by: Alain Michaud <alainm@xxxxxxxxxxxx> > Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@xxxxxxxxxxxx> > Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx> > --- > > Changes in v2: > * Modify locking order for better visibility > > net/bluetooth/l2cap_sock.c | 8 ++++++++ > 1 file changed, 8 insertions(+) patch has been applied to bluetooth-next tree. Regards Marcel
