syzbot


general protection fault in __timer_delete_sync

Status: auto-obsoleted due to no activity on 2025/09/23 21:54
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+1eaee1ec18b9d18ca3b8@syzkaller.appspotmail.com
First crash: 246d, last: 241d
Cause bisection: introduced by (bisect log) :
commit c411c62cc13319533b1861e00cedc4883c3bc1bb
Author: Arseniy Krasnov <avkrasnov@salutedevices.com>
Date: Thu Jan 30 18:43:26 2025 +0000

  Bluetooth: hci_uart: fix race during initialization

Crash: BUG: unable to handle kernel NULL pointer dereference in __timer_delete_sync (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bluetooth?] general protection fault in __timer_delete_sync 1 (3) 2025/02/08 12:33
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: wild-memory-access Read in __timer_delete_sync bcachefs 19 5 434d 501d 27/29 fixed on 2024/08/23 03:09
upstream KASAN: slab-use-after-free Read in __timer_delete_sync mptcp 19 syz error 1 405d 402d 28/29 fixed on 2024/10/22 11:57
Last patch testing requests (5)
Created Duration User Patch Repo Result
2025/09/23 21:26 26m retest repro linux-next OK log
2025/07/15 14:11 30m retest repro linux-next error
2025/05/06 13:39 24m retest repro linux-next error
2025/02/25 11:33 18m retest repro linux-next error
2025/02/08 11:58 27m hdanton@sina.com patch linux-next OK log

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000067: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000338-0x000000000000033f]
CPU: 1 UID: 0 PID: 21046 Comm: syz.5.3038 Not tainted 6.14.0-rc2-next-20250210-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:__lock_acquire+0x6a/0x2100 kernel/locking/lockdep.c:5091
Code: b6 04 30 84 c0 0f 85 f8 16 00 00 45 31 f6 83 3d 1b 17 81 0e 00 0f 84 c8 13 00 00 89 54 24 60 89 5c 24 38 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ff e8 e8 99 8b 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90003547870 EFLAGS: 00010002
RAX: 0000000000000067 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000338
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff20379ef R12: ffff888062335a00
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000338
FS:  00005555943a2500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556edd4648 CR3: 000000007ac38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 __timer_delete_sync+0x148/0x310 kernel/time/timer.c:1644
 del_timer_sync include/linux/timer.h:185 [inline]
 h5_close+0x4b/0x170 drivers/bluetooth/hci_h5.c:257
 hci_uart_tty_close+0x205/0x290 drivers/bluetooth/hci_ldisc.c:557
 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613
 tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781
 tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690
 tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861
 __fput+0x3e9/0x9f0 fs/file_table.c:464
 task_work_run+0x24f/0x310 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x13f/0x340 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3936f8cde9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffca16b2df8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f39371a7ba0 RCX: 00007f3936f8cde9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f39371a7ba0 R08: 0000000000000000 R09: 0000000ca16b30ef
R10: 00007f39371a7ac0 R11: 0000000000000246 R12: 0000000000183698
R13: 00007ffca16b2ef0 R14: ffffffffffffffff R15: 00007ffca16b2f10
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x6a/0x2100 kernel/locking/lockdep.c:5091
Code: b6 04 30 84 c0 0f 85 f8 16 00 00 45 31 f6 83 3d 1b 17 81 0e 00 0f 84 c8 13 00 00 89 54 24 60 89 5c 24 38 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 12 4c 89 ff e8 e8 99 8b 00 48 be 00 00 00 00 00 fc
RSP: 0018:ffffc90003547870 EFLAGS: 00010002
RAX: 0000000000000067 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000338
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000001
R10: dffffc0000000000 R11: fffffbfff20379ef R12: ffff888062335a00
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000338
FS:  00005555943a2500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556edd4648 CR3: 000000007ac38000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	b6 04                	mov    $0x4,%dh
   2:	30 84 c0 0f 85 f8 16 	xor    %al,0x16f8850f(%rax,%rax,8)
   9:	00 00                	add    %al,(%rax)
   b:	45 31 f6             	xor    %r14d,%r14d
   e:	83 3d 1b 17 81 0e 00 	cmpl   $0x0,0xe81171b(%rip)        # 0xe811730
  15:	0f 84 c8 13 00 00    	je     0x13e3
  1b:	89 54 24 60          	mov    %edx,0x60(%rsp)
  1f:	89 5c 24 38          	mov    %ebx,0x38(%rsp)
  23:	4c 89 f8             	mov    %r15,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 30 00          	cmpb   $0x0,(%rax,%rsi,1) <-- trapping instruction
  2e:	74 12                	je     0x42
  30:	4c 89 ff             	mov    %r15,%rdi
  33:	e8 e8 99 8b 00       	call   0x8b9a20
  38:	48                   	rex.W
  39:	be 00 00 00 00       	mov    $0x0,%esi
  3e:	00 fc                	add    %bh,%ah

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/02/11 10:26 linux-next df5d6180169a 43f51a00 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __timer_delete_sync
2025/02/06 17:52 linux-next 808eb958781e 577d049b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __timer_delete_sync
2025/02/06 17:16 linux-next 808eb958781e 577d049b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in __timer_delete_sync
* Struck through repros no longer work on HEAD.