[syzbot] INFO: trying to register non-static key in hci_uart_tty_receive (3)

[syzbot] INFO: trying to register non-static key in hci_uart_tty_receive (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    519d81956ee2 Linux 5.15-rc6
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16787178b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1f7f46d98a0da80e
dashboard link: https://syzkaller.appspot.com/bug?extid=f2725165900304ec97b6
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f2725165900304ec97b6@syzkaller.appspotmail.com

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: 1 PID: 24628 Comm: syz-executor.5 Not tainted 5.15.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __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:939 [inline]
 register_lock_class+0xf79/0x10c0 kernel/locking/lockdep.c:1251
 __lock_acquire+0x105/0x54a0 kernel/locking/lockdep.c:4894
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
 percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
 hci_uart_tty_receive+0xc4/0x710 drivers/bluetooth/hci_ldisc.c:603
 tiocsti drivers/tty/tty_io.c:2310 [inline]
 tty_ioctl+0x909/0x1670 drivers/tty/tty_io.c:2719
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ff49c1bfa39
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff4996b1188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ff49c2c3260 RCX: 00007ff49c1bfa39
RDX: 0000000020000000 RSI: 0000000000005412 RDI: 0000000000000005
RBP: 00007ff49c219c5f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffa845426f R14: 00007ff4996b1300 R15: 0000000000022000


---
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Re: [syzbot] INFO: trying to register non-static key in hci_uart_tty_receive (3)

[Fabio M. De Francesco]

[-- Attachment #1: Type: text/plain, Size: 1061 bytes --]

On Saturday, October 23, 2021 1:54:24 AM CEST syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    519d81956ee2 Linux 5.15-rc6
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=16787178b00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=1f7f46d98a0da80e
> dashboard link: https://syzkaller.appspot.com/bug?
extid=f2725165900304ec97b6
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils 
for Debian) 2.35.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> IMPORTANT: if you fix the issue, please add the following tag to the 
commit:
> Reported-by: syzbot+f2725165900304ec97b6@syzkaller.appspotmail.com
> 
> 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.

Let's try the solution attached.

Fabio

#syz test
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

[-- Attachment #2: hci_ldisc.c.diff --]
[-- Type: text/x-patch, Size: 572 bytes --]

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 5ed2cfa7da1d..18b039c2f3cf 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -499,11 +499,11 @@ static int hci_uart_tty_open(struct tty_struct *tty)
 	hu->alignment = 1;
 	hu->padding = 0;
 
+	percpu_init_rwsem(&hu->proto_lock);
+
 	INIT_WORK(&hu->init_ready, hci_uart_init_work);
 	INIT_WORK(&hu->write_work, hci_uart_write_work);
 
-	percpu_init_rwsem(&hu->proto_lock);
-
 	/* Flush any pending characters in the driver */
 	tty_driver_flush_buffer(tty);
 

Re: [syzbot] INFO: trying to register non-static key in hci_uart_tty_receive (3)

[syzbot]

> On Saturday, October 23, 2021 1:54:24 AM CEST syzbot wrote:
>> Hello,
>> 
>> syzbot found the following issue on:
>> 
>> HEAD commit:    519d81956ee2 Linux 5.15-rc6
>> git tree:       upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=16787178b00000
>> kernel config:  https://syzkaller.appspot.com/x/.config?x=1f7f46d98a0da80e
>> dashboard link: https://syzkaller.appspot.com/bug?
> extid=f2725165900304ec97b6
>> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils 
> for Debian) 2.35.2
>> 
>> Unfortunately, I don't have any reproducer for this issue yet.
>> 
>> IMPORTANT: if you fix the issue, please add the following tag to the 
> commit:
>> Reported-by: syzbot+f2725165900304ec97b6@syzkaller.appspotmail.com
>> 
>> 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.
>
> Let's try the solution attached.
>
> Fabio
>
> #syz test

This crash does not have a reproducer. I cannot test it.

> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master