Bluetooth: hci_serdev: call init_rwsem() before p->open()
PATCH 1/1 Bluetooth: hci_serdev: call init_rwsem() before p->open()
kvartet reported, that hci_uart_tx_wakeup() uses uninitialized rwsem. The problem was in wrong place for percpu_init_rwsem() call.
hci_uart_proto::open() may register a timer whose callback may call hci_uart_tx_wakeup(). There is a chance, that hci_uart_register_device() thread won't be fast enough to call percpu_init_rwsem().
Fix it my moving percpu_init_rwsem() call before p->open().
INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator.
CPU: 2 PID: 18524 Comm: syz-executor.5 Not tainted 5.16.0-rc6 #9 ... Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 assign_lock_key kernel/locking/lockdep.c:951 [inline] register_lock_class+0x148d/0x1950 kernel/locking/lockdep.c:1263 __lock_acquire+0x106/0x57e0 kernel/locking/lockdep.c:4906 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5602 percpu_down_read_trylock include/linux/percpu-rwsem.h:92 [inline] hci_uart_tx_wakeup+0x12e/0x490 drivers/bluetooth/hci_ldisc.c:124 h5_timed_event+0x32f/0x6a0 drivers/bluetooth/hci_h5.c:188 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
--- drivers/bluetooth/hci_serdev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
drivers/bluetooth/hci_serdev.c +2 -1
@@ -305,6 +305,8 @@ int hci_uart_register_device(struct hci_uart *hu,if (err)return err; +percpu_init_rwsem (&hu->proto_lock); + err = p->open (hu);if (err) goto err_open;
@@ -327,7 +329,6 @@ int hci_uart_register_device(struct hci_uart *hu,INIT_WORK (&hu->init_ready, hci_uart_init_work);INIT_WORK (&hu->write_work, hci_uart_write_work); -percpu_init_rwsem (&hu->proto_lock);/* Only when vendor specific setup callback is provided, consider * the manufacturer information valid. This avoids filling in the
Signature · 1 line
2.34.1
Marcel Holtmann
maintainerHi Pavel,
Quoted 29 lines
kvartet reported, that
hci_uart_tx_wakeup()uses uninitialized rwsem. The problem was in wrong place forpercpu_init_rwsem()call.
hci_uart_proto::open()may register a timer whose callback may callhci_uart_tx_wakeup(). There is a chance, thathci_uart_register_device()thread won't be fast enough to callpercpu_init_rwsem().Fix it my moving
percpu_init_rwsem()call beforep->open().INFO: trying to register non-static key.
The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator.CPU: 2 PID: 18524 Comm: syz-executor.5 Not tainted 5.16.0-rc6 #9 ... Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 assign_lock_key kernel/locking/lockdep.c:951 [inline] register_lock_class+0x148d/0x1950 kernel/locking/lockdep.c:1263 __lock_acquire+0x106/0x57e0 kernel/locking/lockdep.c:4906 lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5602 percpu_down_read_trylock include/linux/percpu-rwsem.h:92 [inline] hci_uart_tx_wakeup+0x12e/0x490 drivers/bluetooth/hci_ldisc.c:124 h5_timed_event+0x32f/0x6a0 drivers/bluetooth/hci_h5.c:188 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
Quoted 6 lines
Fixes d73e17281665 ("Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops")Reported-by Yiru Xu <[email protected]>Signed-off-by Pavel Skripkin <[email protected]>---
drivers/bluetooth/hci_serdev.c| 3 ++-1 file changed, 2 insertions(+), 1 deletion(-)
patch has been applied to bluetooth-next tree.
Regards
Marcel