[syzbot] WARNING in notifier_chain_register

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cb71b93c2dc3 Add linux-next specific files for 20220628
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=168bb25bf00000
kernel config: https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb
dashboard link: https://syzkaller.appspot.com/bug?extid=5214f8dac5863061e37c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13915d68080000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13dee200080000

The issue was bisected to:

commit ff7f2926114d3a50f5ffe461a9bce8d761748da5
Author: Vasyl Vavrychuk <vasyl.v...@opensynergy.com>
Date: Tue Apr 26 08:18:23 2022 +0000

Bluetooth: core: Fix missing power_on work cancel on HCI close

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15ea8982080000
final oops: https://syzkaller.appspot.com/x/report.txt?x=17ea8982080000
console output: https://syzkaller.appspot.com/x/log.txt?x=13ea8982080000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5214f8...@syzkaller.appspotmail.com
Fixes: ff7f2926114d ("Bluetooth: core: Fix missing power_on work cancel on HCI close")

------------[ cut here ]------------
notifier callback hci_suspend_notifier already registered
WARNING: CPU: 1 PID: 3898 at kernel/notifier.c:28 notifier_chain_register kernel/notifier.c:28 [inline]
WARNING: CPU: 1 PID: 3898 at kernel/notifier.c:28 notifier_chain_register+0x156/0x210 kernel/notifier.c:22
Modules linked in:
CPU: 1 PID: 3898 Comm: syz-executor172 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:notifier_chain_register kernel/notifier.c:28 [inline]
RIP: 0010:notifier_chain_register+0x156/0x210 kernel/notifier.c:22
Code: 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 a5 00 00 00 49 8b 75 00 48 c7 c7 c0 d0 cb 89 e8 14 f5 e3 07 <0f> 0b 41 bc ef ff ff ff e8 5d 6f 2a 00 44 89 e0 48 83 c4 18 5b 5d
RSP: 0018:ffffc9000367fca8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88807ae11180 RCX: 0000000000000000
RDX: ffff888076fa3a80 RSI: ffffffff81610608 RDI: fffff520006cff87
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 0000000000000000
R13: ffff88807ae11180 R14: ffff88801bb79188 R15: dffffc0000000000
FS: 0000555556682300(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4d8d866e8 CR3: 0000000070960000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__blocking_notifier_chain_register kernel/notifier.c:266 [inline]
blocking_notifier_chain_register+0x6f/0xc0 kernel/notifier.c:284
hci_register_suspend_notifier net/bluetooth/hci_core.c:2752 [inline]
hci_register_suspend_notifier+0x9d/0xc0 net/bluetooth/hci_core.c:2746
hci_sock_bind+0x141a/0x1630 net/bluetooth/hci_sock.c:1234
__sys_bind+0x1e9/0x250 net/socket.c:1776
__do_sys_bind net/socket.c:1787 [inline]
__se_sys_bind net/socket.c:1785 [inline]
__x64_sys_bind+0x6f/0xb0 net/socket.c:1785
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+0x46/0xb0
RIP: 0033:0x7fe4d8d314a9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 d1 15 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe5c71ae28 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fe4d8d314a9
RDX: 0000000000000006 RSI: 0000000020000240 RDI: 0000000000000004
RBP: 0000000000000003 R08: 0000000000000150 R09: 0000000000000150
R10: 0000000000000000 R11: 0000000000000246 R12: 00005555566822b8
R13: 0000000000000011 R14: 00007ffe5c71ae90 R15: 00007ffe5c71ae48
</TASK>


---
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See https://goo.gl/tpsmEJ for more information about syzbot.
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Hillf Danton]

On Wed, 06 Jul 2022 06:50:29 -0700

See if it makes sense to delete the un/register of notifier.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git cb71b93c2dc3

--- y/net/bluetooth/hci_sock.c
+++ h/net/bluetooth/hci_sock.c
@@ -1216,7 +1216,6 @@ static int hci_sock_bind(struct socket *
}

mgmt_index_removed(hdev);
- hci_unregister_suspend_notifier(hdev);

err = hci_dev_open(hdev->id);
if (err) {
@@ -1231,7 +1230,6 @@ static int hci_sock_bind(struct socket *
err = 0;
} else {
hci_dev_clear_flag(hdev, HCI_USER_CHANNEL);
- hci_register_suspend_notifier(hdev);
mgmt_index_added(hdev);
hci_dev_put(hdev);
goto done;
--

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in notifier_chain_register

------------[ cut here ]------------
notifier callback hci_suspend_notifier already registered

WARNING: CPU: 1 PID: 4179 at kernel/notifier.c:28 notifier_chain_register kernel/notifier.c:28 [inline]
WARNING: CPU: 1 PID: 4179 at kernel/notifier.c:28 notifier_chain_register+0x156/0x210 kernel/notifier.c:22
Modules linked in:
CPU: 1 PID: 4179 Comm: syz-executor.3 Not tainted 5.19.0-rc4-next-20220628-syzkaller-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:notifier_chain_register kernel/notifier.c:28 [inline]
RIP: 0010:notifier_chain_register+0x156/0x210 kernel/notifier.c:22
Code: 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 a5 00 00 00 49 8b 75 00 48 c7 c7 c0 d0 cb 89 e8 14 f5 e3 07 <0f> 0b 41 bc ef ff ff ff e8 5d 6f 2a 00 44 89 e0 48 83 c4 18 5b 5d

RSP: 0018:ffffc9000373fd58 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff88801e825180 RCX: 0000000000000000
RDX: ffff8880735ad7c0 RSI: ffffffff81610608 RDI: fffff520006e7f9d

RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 0000000000000000

R13: ffff88801e825180 R14: ffffffff8caa8ce8 R15: dffffc0000000000
FS: 0000555556946400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 0000555556109708 CR3: 0000000076371000 CR4: 00000000003506e0

DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__blocking_notifier_chain_register kernel/notifier.c:266 [inline]
blocking_notifier_chain_register+0x6f/0xc0 kernel/notifier.c:284
hci_register_suspend_notifier net/bluetooth/hci_core.c:2752 [inline]
hci_register_suspend_notifier+0x9d/0xc0 net/bluetooth/hci_core.c:2746

hci_sock_release+0x4a2/0x520 net/bluetooth/hci_sock.c:890
__sock_release+0xcd/0x280 net/socket.c:650
sock_close+0x18/0x20 net/socket.c:1365
__fput+0x277/0x9d0 fs/file_table.c:317
task_work_run+0xdd/0x1a0 kernel/task_work.c:177
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:169 [inline]
exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f988dc3bd4b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffcc6777580 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f988dc3bd4b
RDX: 00007f988dda02e8 RSI: ffffffffffffffff RDI: 0000000000000004
RBP: 00007f988dd9d960 R08: 0000000000000000 R09: 00007f988dda02f0
R10: 00007ffcc6777680 R11: 0000000000000293 R12: 00000000000147b9
R13: 00007ffcc6777680 R14: 00007f988dd9bf60 R15: 0000000000000032
</TASK>


Tested on:

commit: cb71b93c Add linux-next specific files for 20220628
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
console output: https://syzkaller.appspot.com/x/log.txt?x=15640350080000

kernel config: https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb
dashboard link: https://syzkaller.appspot.com/bug?extid=5214f8dac5863061e37c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=1059e134080000

[Hillf Danton]

On Wed, 06 Jul 2022 06:50:29 -0700

See if it makes sense to delete the un/register of notifier.

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git cb71b93c2dc3

--- y/net/bluetooth/hci_sock.c
+++ h/net/bluetooth/hci_sock.c

@@ -887,7 +887,6 @@ static int hci_sock_release(struct socke
*/
hci_dev_do_close(hdev);

hci_dev_clear_flag(hdev, HCI_USER_CHANNEL);
- hci_register_suspend_notifier(hdev);
mgmt_index_added(hdev);
}

@@ -1216,7 +1215,6 @@ static int hci_sock_bind(struct socket *

}

mgmt_index_removed(hdev);
- hci_unregister_suspend_notifier(hdev);

err = hci_dev_open(hdev->id);
if (err) {

@@ -1231,7 +1229,6 @@ static int hci_sock_bind(struct socket *

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+5214f8...@syzkaller.appspotmail.com

Tested on:

commit: cb71b93c Add linux-next specific files for 20220628
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git

console output: https://syzkaller.appspot.com/x/log.txt?x=14bedff4080000

kernel config: https://syzkaller.appspot.com/x/.config?x=badbc1adb2d582eb
dashboard link: https://syzkaller.appspot.com/bug?extid=5214f8dac5863061e37c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

patch: https://syzkaller.appspot.com/x/patch.diff?x=163fa292080000

Note: testing is done by a robot and is best-effort only.

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.