syzbot


possible deadlock in blocking_notifier_call_chain

Status: upstream: reported C repro on 2019/12/29 21:56
Reported-by: syzbot+837c6b903aaf83b8f420@syzkaller.appspotmail.com
First crash: 1609d, last: 446d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in blocking_notifier_call_chain kernel 1 117d 116d 0/26 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 299d 442d 0/3 upstream: reported C repro on 2023/03/10 08:18
linux-4.14 possible deadlock in blocking_notifier_call_chain C inconclusive 132 449d 1626d 0/1 upstream: reported C repro on 2019/12/12 18:02
Fix bisection attempts (5)
Created Duration User Patch Repo Result
2021/06/09 17:29 32m bisect fix linux-4.19.y job log (0) log
2020/08/17 01:02 27m bisect fix linux-4.19.y job log (0) log
2020/07/18 00:34 27m bisect fix linux-4.19.y job log (0) log
2020/06/14 18:38 24m bisect fix linux-4.19.y job log (0) log
2020/05/15 17:25 28m bisect fix linux-4.19.y job log (0) log

Sample crash report:
============================================
WARNING: possible recursive locking detected
4.19.211-syzkaller #0 Not tainted
--------------------------------------------
syz-executor301/8133 is trying to acquire lock:
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain kernel/notifier.c:328 [inline]
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain+0x6f/0xa0 kernel/notifier.c:325

but task is already holding lock:
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain kernel/notifier.c:328 [inline]
0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain+0x6f/0xa0 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-executor301/8133:
 #0: 00000000c985598e (console_lock){+.+.}, at: do_fb_ioctl+0x772/0xb50 drivers/video/fbdev/core/fbmem.c:1210
 #1: 00000000d3bb56cf (&fb_info->lock){+.+.}, at: lock_fb_info drivers/video/fbdev/core/fbmem.c:81 [inline]
 #1: 00000000d3bb56cf (&fb_info->lock){+.+.}, at: do_fb_ioctl+0x77c/0xb50 drivers/video/fbdev/core/fbmem.c:1211
 #2: 0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #2: 0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: __blocking_notifier_call_chain kernel/notifier.c:304 [inline]
 #2: 0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain kernel/notifier.c:328 [inline]
 #2: 0000000049dd2a93 ((fb_notifier_list).rwsem){++++}, at: blocking_notifier_call_chain+0x6f/0xa0 kernel/notifier.c:325

stack backtrace:
CPU: 0 PID: 8133 Comm: syz-executor301 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_deadlock_bug kernel/locking/lockdep.c:1764 [inline]
 check_deadlock kernel/locking/lockdep.c:1808 [inline]
 validate_chain kernel/locking/lockdep.c:2404 [inline]
 __lock_acquire.cold+0x121/0x57e kernel/locking/lockdep.c:3416
 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908
 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+0x6f/0xa0 kernel/notifier.c:325
 fb_set_var+0xd9a/0xf90 drivers/video/fbdev/core/fbmem.c:1052
 fbcon_switch+0x425/0x1ba0 drivers/video/fbdev/core/fbcon.c:2088
 redraw_screen+0x37d/0x870 drivers/tty/vt/vt.c:1015
 fbcon_blank+0xae6/0xec0 drivers/video/fbdev/core/fbcon.c:2226
 do_unblank_screen+0x241/0x610 drivers/tty/vt/vt.c:4294
 fbcon_fb_blanked drivers/video/fbdev/core/fbcon.c:2973 [inline]
 fbcon_event_notify+0x1a3a/0x1d80 drivers/video/fbdev/core/fbcon.c:3091
 notifier_call_chain+0xc0/0x230 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+0x85/0xa0 kernel/notifier.c:325
 fb_blank+0x195/0x1d0 drivers/video/fbdev/core/fbmem.c:1080
 do_fb_ioctl+0x7ec/0xb50 drivers/video/fbdev/core/fbmem.c:1216
 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1240
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f36d2d29269
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe8aaad968 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000000f4240 RCX: 00007f36d2d29269
RDX: 0000000000000000 RSI: 0000000000004611 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 00007ffe8aaad3e0 R11: 0000000000000246 R12: 000000000000a22c
R13: 00007ffe8aaad97c R14: 00007ffe8aaad990 R15: 00007ffe8aaad980

Crashes (183):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/09/11 19:02 linux-4.19.y 3f8a27f9e27b 356d8217 .config console log report syz C ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/22 09:56 linux-4.19.y 3f8a27f9e27b 7268fa62 .config console log report syz C ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2021/03/15 03:47 linux-4.19.y 030194a5b292 cc1cff8f .config console log report syz C ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2021/02/12 11:00 linux-4.19.y 811218eceeaa a5f86b15 .config console log report syz C ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2020/03/29 21:46 linux-4.19.y 54b4fa6d3955 05736b29 .config console log report syz C ci2-linux-4-19
2023/03/06 23:23 linux-4.19.y 3f8a27f9e27b f8902b57 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2023/02/05 17:36 linux-4.19.y 3f8a27f9e27b be607b78 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2023/01/30 00:38 linux-4.19.y 3f8a27f9e27b 9dfcf09c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2023/01/12 20:14 linux-4.19.y 3f8a27f9e27b 96166539 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2023/01/07 05:57 linux-4.19.y 3f8a27f9e27b 1dac8c7a .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2023/01/02 19:15 linux-4.19.y 3f8a27f9e27b ab32d508 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/12/16 22:51 linux-4.19.y 3f8a27f9e27b 05494336 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/12/10 12:51 linux-4.19.y 3f8a27f9e27b 67be1ae7 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/11/25 23:04 linux-4.19.y 3f8a27f9e27b f4470a7b .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/11/25 07:32 linux-4.19.y 3f8a27f9e27b 74a66371 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/11/22 12:33 linux-4.19.y 3f8a27f9e27b 1c576c23 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/11/13 13:15 linux-4.19.y 3f8a27f9e27b f42ee5d8 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/11/08 01:26 linux-4.19.y 3f8a27f9e27b 6feb842b .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/10/20 02:49 linux-4.19.y 3f8a27f9e27b b31320fc .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/10/06 00:01 linux-4.19.y 3f8a27f9e27b 2c6543ad .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/28 08:19 linux-4.19.y 3f8a27f9e27b 75c78242 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/22 02:14 linux-4.19.y 3f8a27f9e27b 60af5050 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/15 18:52 linux-4.19.y 3f8a27f9e27b dd9a85ff .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/11 06:41 linux-4.19.y 3f8a27f9e27b 356d8217 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/10 23:19 linux-4.19.y 3f8a27f9e27b 356d8217 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/09 17:50 linux-4.19.y 3f8a27f9e27b 90058bdc .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/06 08:02 linux-4.19.y 3f8a27f9e27b 9dcd38fc .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/09/01 23:50 linux-4.19.y 3f8a27f9e27b 86c46e46 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/08/10 12:42 linux-4.19.y 3f8a27f9e27b aaa9eaa0 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/08/10 02:14 linux-4.19.y 3f8a27f9e27b c2a623d6 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/08/05 12:11 linux-4.19.y 3f8a27f9e27b a65a7ce9 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/08/03 18:29 linux-4.19.y 3f8a27f9e27b 1c9013ac .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/08/02 13:04 linux-4.19.y 3f8a27f9e27b fef302b1 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/29 18:24 linux-4.19.y 3f8a27f9e27b fef302b1 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/21 14:58 linux-4.19.y 3f8a27f9e27b 6e67af9d .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/18 16:52 linux-4.19.y 3f8a27f9e27b ff988920 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/12 08:15 linux-4.19.y 3f8a27f9e27b da3d6955 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/11 18:23 linux-4.19.y 3f8a27f9e27b f3f217ff .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/09 10:46 linux-4.19.y 3f8a27f9e27b b5765a15 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/08 05:39 linux-4.19.y 3f8a27f9e27b bff65f44 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/07/01 04:47 linux-4.19.y 3f8a27f9e27b 1434eec0 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/06/26 14:57 linux-4.19.y 3f8a27f9e27b a371c43c .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/06/16 07:12 linux-4.19.y 3f8a27f9e27b 1719ee24 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/24 18:49 linux-4.19.y 3f8a27f9e27b fcfad4ff .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/23 17:19 linux-4.19.y 3f8a27f9e27b 4c7657cb .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/16 00:26 linux-4.19.y 3f8a27f9e27b 744a39e2 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/14 11:38 linux-4.19.y 3f8a27f9e27b 744a39e2 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/05 14:58 linux-4.19.y 3f8a27f9e27b b3f09415 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2022/05/05 00:28 linux-4.19.y 3f8a27f9e27b dc9e5259 .config console log report info ci2-linux-4-19 possible deadlock in blocking_notifier_call_chain
2021/01/17 03:48 linux-4.19.y 675cc038067f 65a7a854 .config console log report info ci2-linux-4-19
2019/12/29 21:55 linux-4.19.y 672481c2deff af6b8ef8 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.