syzbot


possible deadlock in blocking_notifier_call_chain

Status: upstream: reported C repro on 2019/12/12 18:02
Reported-by: syzbot+347efd5cd55d8ca41479@syzkaller.appspotmail.com
First crash: 1656d, last: 479d
Fix bisection the fix commit could be any of (bisect log):
  c10b57a567e4 Linux 4.14.176
  4139fb08c05f Linux 4.14.187
  
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 possible deadlock in blocking_notifier_call_chain C 183 476d 1639d 0/1 upstream: reported C repro on 2019/12/29 21:56
upstream possible deadlock in blocking_notifier_call_chain kernel 1 146d 146d 0/27 auto-obsoleted due to no activity on 2024/05/09 04:21
linux-5.15 possible deadlock in blocking_notifier_call_chain origin:lts-only C done 386 329d 472d 0/3 upstream: reported C repro on 2023/03/10 08:18
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2020/07/01 10:08 29m (2) bisect fix linux-4.14.y job log (2)
2020/05/19 10:32 26m bisect fix linux-4.14.y job log (0) log

Sample crash report:
============================================
WARNING: possible recursive locking detected
4.14.292-syzkaller #0 Not tainted
--------------------------------------------
syz-executor297/7987 is trying to acquire lock:
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325

but task is already holding lock:
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock((fb_notifier_list).rwsem);
  lock((fb_notifier_list).rwsem);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by syz-executor297/7987:
 #0:  (console_lock){+.+.}, at: [<ffffffff833680da>] do_fb_ioctl+0x81a/0xa70 drivers/video/fbdev/core/fbmem.c:1223
 #1:  (&fb_info->lock){+.+.}, at: [<ffffffff833680e4>] lock_fb_info drivers/video/fbdev/core/fbmem.c:82 [inline]
 #1:  (&fb_info->lock){+.+.}, at: [<ffffffff833680e4>] do_fb_ioctl+0x824/0xa70 drivers/video/fbdev/core/fbmem.c:1224
 #2:  ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #2:  ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 #2:  ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 #2:  ((fb_notifier_list).rwsem){++++}, at: [<ffffffff8137bdf3>] blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325

stack backtrace:
CPU: 1 PID: 7987 Comm: syz-executor297 Not tainted 4.14.292-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 print_deadlock_bug kernel/locking/lockdep.c:1800 [inline]
 check_deadlock kernel/locking/lockdep.c:1847 [inline]
 validate_chain kernel/locking/lockdep.c:2448 [inline]
 __lock_acquire.cold+0x180/0x97c kernel/locking/lockdep.c:3491
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 down_read+0x36/0x80 kernel/locking/rwsem.c:24
 __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x63/0x90 kernel/notifier.c:325
 fb_set_var+0xbc8/0xdc0 drivers/video/fbdev/core/fbmem.c:1065
 fbcon_switch+0x3d9/0x19e0 drivers/video/fbdev/core/fbcon.c:2066
 redraw_screen+0x32c/0x790 drivers/tty/vt/vt.c:689
 fbcon_blank+0x986/0xd50 drivers/video/fbdev/core/fbcon.c:2204
 do_unblank_screen+0x1fd/0x4e0 drivers/tty/vt/vt.c:3954
 fbcon_fb_blanked drivers/video/fbdev/core/fbcon.c:2933 [inline]
 fbcon_event_notify+0x1445/0x1760 drivers/video/fbdev/core/fbcon.c:3051
 notifier_call_chain+0x108/0x1a0 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 blocking_notifier_call_chain+0x79/0x90 kernel/notifier.c:325
 fb_blank+0x14c/0x190 drivers/video/fbdev/core/fbmem.c:1093
 do_fb_ioctl+0x894/0xa70 drivers/video/fbdev/core/fbmem.c:1229
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1253
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7fb332166279
RSP: 002b:00007fffe071ff58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007fb332166279
RDX: 0000000000000000 RSI: 0000000000004611 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 00007fffe071f9d0 R11: 0000000000000246 R12: 00007fb332129a50
R13: 0000000000000000 R14: 00007fffe071ff80 R15: 00007fffe071ff70

Crashes (132):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/09/11 16:56 linux-4.14.y 65640c873dcf 356d8217 .config console log report syz C ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/05/22 09:33 linux-4.14.y dffb5c6ff09c 7268fa62 .config console log report syz C ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2021/03/12 03:42 linux-4.14.y c7150cd2fa8c 429d8a6b .config console log report syz C ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2021/02/27 17:15 linux-4.14.y 3242aa3a635c 4c37c133 .config console log report syz C ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2021/02/05 10:06 linux-4.14.y 2c8a3fceddf0 23a562df .config console log report syz C ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2020/04/15 13:19 linux-4.14.y c10b57a567e4 3f3c5574 .config console log report syz C ci2-linux-4-14
2023/03/03 15:17 linux-4.14.y 7878a41b6cc1 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2023/03/03 08:23 linux-4.14.y 7878a41b6cc1 f8902b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2023/02/12 06:52 linux-4.14.y a8ad60f2af58 93e26d60 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2023/01/29 16:56 linux-4.14.y 3949d1610004 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2023/01/05 12:41 linux-4.14.y c4215ee4771b 1dac8c7a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/12/26 09:19 linux-4.14.y c4215ee4771b 9da18ae8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/12/02 09:31 linux-4.14.y 179ef7fe8677 e080de16 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/11/27 19:27 linux-4.14.y 179ef7fe8677 f4470a7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/11/15 10:36 linux-4.14.y e911713e40ca 97de9cfc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/11/10 12:59 linux-4.14.y a901bb6c7db7 b2488a87 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/11/09 09:04 linux-4.14.y a901bb6c7db7 5fa28208 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/11/06 11:25 linux-4.14.y a901bb6c7db7 6d752409 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/10/24 06:51 linux-4.14.y 9d5c0b3a8e1a 23bf86af .config console log report info [disk image] [vmlinux] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/10/16 17:34 linux-4.14.y 9d5c0b3a8e1a 67cb024c .config console log report info [disk image] [vmlinux] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/10/01 22:00 linux-4.14.y 9d5c0b3a8e1a feb56351 .config console log report info [disk image] [vmlinux] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/09/26 01:21 linux-4.14.y 4edbf74132a4 0042f2b4 .config console log report info [disk image] [vmlinux] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/09/24 07:46 linux-4.14.y 4edbf74132a4 0042f2b4 .config console log report info [disk image] [vmlinux] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/09/17 16:32 linux-4.14.y 5df8b4735177 dd9a85ff .config console log report info [disk image] [vmlinux] ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/09/11 16:08 linux-4.14.y 65640c873dcf 356d8217 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/27 19:27 linux-4.14.y e548869f356f 07177916 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/27 18:01 linux-4.14.y e548869f356f 07177916 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/25 00:38 linux-4.14.y b641242202ed 514514f6 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/24 00:56 linux-4.14.y b641242202ed cea8b0f7 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/23 01:29 linux-4.14.y b641242202ed 26a13b38 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/19 07:28 linux-4.14.y b641242202ed 26a13b38 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/15 13:36 linux-4.14.y b641242202ed 8dfcaa3d .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/13 15:11 linux-4.14.y b641242202ed 8dfcaa3d .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/09 23:22 linux-4.14.y b641242202ed c2a623d6 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/08 03:23 linux-4.14.y b641242202ed 88e3a122 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/08/03 11:16 linux-4.14.y b641242202ed 1c9013ac .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/31 00:19 linux-4.14.y b641242202ed fef302b1 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/30 15:16 linux-4.14.y b641242202ed fef302b1 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/25 17:38 linux-4.14.y 9c3bf9cf362f 664c519c .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/23 03:01 linux-4.14.y 9c3bf9cf362f 22343af4 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/10 09:58 linux-4.14.y 1048779a1d7d b5765a15 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/10 01:34 linux-4.14.y 1048779a1d7d b5765a15 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/09 03:48 linux-4.14.y 1048779a1d7d b5765a15 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/06 09:53 linux-4.14.y ed2e96e11936 bff65f44 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/07/01 17:18 linux-4.14.y f051383ef03b 1434eec0 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/06/22 00:29 linux-4.14.y 84bae26850e3 0fc5c330 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/06/19 03:56 linux-4.14.y 84bae26850e3 8f633d84 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/06/01 14:12 linux-4.14.y 501eec4f9e13 3666edfe .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2022/05/30 12:26 linux-4.14.y 501eec4f9e13 a46af346 .config console log report info ci2-linux-4-14 possible deadlock in blocking_notifier_call_chain
2021/01/11 17:44 linux-4.14.y ec822b3e8bf4 2c1f2513 .config console log report info ci2-linux-4-14
2019/12/12 18:01 linux-4.14.y a844dc4c5442 08003f64 .config console log report ci2-linux-4-14
* Struck through repros no longer work on HEAD.