syzbot


WARNING: locking bug in sched_core_balance

Status: upstream: reported C repro on 2024/06/21 21:02
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+14641d8d78cc029add8a@syzkaller.appspotmail.com
First crash: 333d, last: 55d
Cause bisection: introduced by (bisect log) :
commit 7908632f2927b65f7486ae6b67c24071666ba43f
Author: MaΓ­ra Canal <mcanal@igalia.com>
Date: Thu Sep 14 10:19:02 2023 +0000

  Revert "drm/vkms: Fix race-condition between the hrtimer and the atomic commit"

Crash: WARNING: locking bug in sched_core_balance (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [kernel?] WARNING: locking bug in sched_core_balance 1 (5) 2025/01/02 12:15
[syzbot] Monthly io-uring report (Dec 2024) 0 (1) 2024/12/26 09:01
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: slab-use-after-free Read in sched_core_balance kernel 21 262d 269d 0/28 closed as invalid on 2024/09/13 10:29
Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/04/05 17:07 21m retest repro upstream report log
2025/04/05 17:07 21m retest repro upstream report log
2025/04/05 17:07 1h55m retest repro upstream report log

Sample crash report:
BUG: unable to handle page fault for address: fffffbfff3f8171b
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 23ffe4067 P4D 23ffe4067 PUD 23ffe3067 PMD 0 
Oops: Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x82/0x290 mm/kasan/generic.c:189
Code: 01 00 00 00 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd <41> 80 3b 00 0f 85 c9 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00
RSP: 0018:ffffffff8e607640 EFLAGS: 00010086
RAX: 000000000172ce01 RBX: 1ffffffff3f8171b RCX: ffffffff817ac174
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff9fc0b8d8
RBP: ffffffffffffffff R08: ffffffff9fc0b8df R09: 1ffffffff3f8171b
R10: dffffc0000000000 R11: fffffbfff3f8171b R12: ffffffff8e697084
R13: ffffffff8e6965c0 R14: dffffc0000000001 R15: fffffbfff3f8171c
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff3f8171b CR3: 0000000077460000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 __lock_acquire+0xc94/0x2100 kernel/locking/lockdep.c:5196
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378
 raw_spin_rq_lock_nested+0xb0/0x140 kernel/sched/core.c:606
 raw_spin_rq_lock kernel/sched/sched.h:1523 [inline]
 raw_spin_rq_lock_irq kernel/sched/sched.h:1529 [inline]
 sched_core_balance+0xd87/0xf50 kernel/sched/core.c:6411
 do_balance_callbacks kernel/sched/core.c:5021 [inline]
 __balance_callbacks+0x18a/0x280 kernel/sched/core.c:5075
 finish_lock_switch kernel/sched/core.c:5122 [inline]
 finish_task_switch+0x1d3/0x870 kernel/sched/core.c:5241
 context_switch kernel/sched/core.c:5372 [inline]
 __schedule+0x1858/0x4c30 kernel/sched/core.c:6756
 schedule_idle+0x56/0x90 kernel/sched/core.c:6874
 do_idle+0x567/0x5c0 kernel/sched/idle.c:353
 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423
 rest_init+0x2dc/0x300 init/main.c:747
 start_kernel+0x47f/0x500 init/main.c:1102
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:507
 x86_64_start_kernel+0x9f/0xa0 arch/x86/kernel/head64.c:488
 common_startup_64+0x13e/0x147
 </TASK>
Modules linked in:
CR2: fffffbfff3f8171b
---[ end trace 0000000000000000 ]---
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x82/0x290 mm/kasan/generic.c:189
Code: 01 00 00 00 00 fc ff df 4f 8d 3c 31 4c 89 fd 4c 29 dd 48 83 fd 10 7f 29 48 85 ed 0f 84 3e 01 00 00 4c 89 cd 48 f7 d5 48 01 dd <41> 80 3b 00 0f 85 c9 01 00 00 49 ff c3 48 ff c5 75 ee e9 1e 01 00
RSP: 0018:ffffffff8e607640 EFLAGS: 00010086
RAX: 000000000172ce01 RBX: 1ffffffff3f8171b RCX: ffffffff817ac174
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff9fc0b8d8
RBP: ffffffffffffffff R08: ffffffff9fc0b8df R09: 1ffffffff3f8171b
R10: dffffc0000000000 R11: fffffbfff3f8171b R12: ffffffff8e697084
R13: ffffffff8e6965c0 R14: dffffc0000000001 R15: fffffbfff3f8171c
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfff3f8171b CR3: 0000000077460000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess), 7 bytes skipped:
   0:	df 4f 8d             	fisttps -0x73(%rdi)
   3:	3c 31                	cmp    $0x31,%al
   5:	4c 89 fd             	mov    %r15,%rbp
   8:	4c 29 dd             	sub    %r11,%rbp
   b:	48 83 fd 10          	cmp    $0x10,%rbp
   f:	7f 29                	jg     0x3a
  11:	48 85 ed             	test   %rbp,%rbp
  14:	0f 84 3e 01 00 00    	je     0x158
  1a:	4c 89 cd             	mov    %r9,%rbp
  1d:	48 f7 d5             	not    %rbp
  20:	48 01 dd             	add    %rbx,%rbp
* 23:	41 80 3b 00          	cmpb   $0x0,(%r11) <-- trapping instruction
  27:	0f 85 c9 01 00 00    	jne    0x1f6
  2d:	49 ff c3             	inc    %r11
  30:	48 ff c5             	inc    %rbp
  33:	75 ee                	jne    0x23
  35:	e9                   	.byte 0xe9
  36:	1e                   	(bad)
  37:	01 00                	add    %eax,(%rax)

Crashes (105):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/01 20:58 upstream ccb98ccef0e5 d3ccff63 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/01/17 11:25 upstream ce69b4019001 f9e07a6e .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/25 06:52 upstream 9b2ffa6148b1 444551c4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/03/20 11:54 upstream a7f2e10ecd8f 3b7445cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/03/13 06:44 upstream 0fed89a961ea 1a5d9317 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/03/11 14:24 upstream 4d872d51bc9d 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/03/08 08:02 upstream 21e4543a2e2f 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/03/04 14:34 upstream 99fa936e8e4f c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/02/25 18:47 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/02/14 11:21 upstream ab68d7eb7b1a d9a046cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/02/12 09:54 upstream 09fbf3d50205 f2baddf5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/02/09 17:22 upstream 9946eaf552b1 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/01/20 00:44 upstream 9528d418de4d f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/01/15 23:28 upstream 619f0b6fad52 968edaf4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/01/15 10:40 upstream 619f0b6fad52 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/01/14 22:06 upstream c3812b15000c 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/01/09 11:30 upstream eea6e4b4dfb8 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/01/06 18:43 upstream 5428dc1906dd f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/31 01:39 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/28 03:15 upstream 8379578b11d5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/22 23:05 upstream bcde95ce32b6 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/16 04:38 upstream dccbe2047a5b 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/15 03:11 upstream a0e3919a2df2 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/13 08:37 upstream 150b567e0d57 3547e30f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/12 16:05 upstream 231825b2e1ff 941924eb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/12/09 14:19 upstream fac04efc5c79 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/06/19 13:36 upstream 2ccbdf43d5e7 41b7e219 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2024/06/17 20:56 upstream 2ccbdf43d5e7 1f11cfd7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING: locking bug in sched_core_balance
2025/03/22 13:12 upstream 88d324e69ea9 c6512ef7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: wild-memory-access Read in sched_core_balance
2025/03/22 03:22 upstream 88d324e69ea9 62330552 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: wild-memory-access Read in sched_core_balance
2025/03/22 01:07 upstream 88d324e69ea9 62330552 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: wild-memory-access Read in sched_core_balance
2025/03/19 05:45 upstream 81e4f8d68c66 22a6c2b1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: wild-memory-access Read in sched_core_balance
2025/03/08 01:34 upstream 00a7d39898c8 7e3bd60d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/03/07 09:17 upstream f315296c92fd 831e3629 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/03/04 03:19 upstream 99fa936e8e4f c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/03/02 02:47 upstream 03d38806a902 c3901742 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/27 02:05 upstream 5394eea10651 6a8fcbc4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/25 14:53 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/24 08:31 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/24 06:40 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/11 06:20 upstream febbc555cf0f 43f51a00 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/08 07:07 upstream 7ee983c850b4 a4f327c2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/06 13:13 upstream 92514ef226f5 577d049b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/02/01 23:26 upstream 69e858e0b8b2 0dff8567 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: wild-memory-access Read in sched_core_balance
2025/01/21 21:42 upstream b9d8a295ed6b 6e87cfa2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root KASAN: wild-memory-access Read in sched_core_balance
2025/01/06 10:05 upstream ab75170520d4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/01/03 18:06 upstream 0bc21e701a6f f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/01/02 03:34 upstream 56e6a3499e14 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2025/01/01 15:34 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2024/12/30 17:58 upstream fc033cf25e61 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2024/12/30 11:32 upstream fc033cf25e61 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2024/12/25 05:33 upstream 9b2ffa6148b1 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
2024/12/22 13:06 upstream 48f506ad0b68 d7f584ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root BUG: unable to handle kernel paging request in sched_core_balance
* Struck through repros no longer work on HEAD.