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authorPavel Skripkin <paskripkin@gmail.com>2022-01-13 16:27:04 +0300
committerMarcel Holtmann <marcel@holtmann.org>2022-01-21 23:46:48 +0100
commit9d7cbe2b9cf5f650067df4f402fdd799d4bbb4e1 (patch)
tree1f055ae3e30424c462aed9361caf1cce289d2ce6 /drivers/bluetooth
parenta86974f75e8806bc357a9be02f9bde083f40b4ae (diff)
downloadlinux-9d7cbe2b9cf5f650067df4f402fdd799d4bbb4e1.tar.bz2
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 Fixes: d73e17281665 ("Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops") Reported-by: Yiru Xu <xyru1999@gmail.com> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'drivers/bluetooth')
-rw-r--r--drivers/bluetooth/hci_serdev.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
index 3b00d82d36cf..4cda890ce647 100644
--- a/drivers/bluetooth/hci_serdev.c
+++ b/drivers/bluetooth/hci_serdev.c
@@ -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