syzbot


KASAN: slab-out-of-bounds Write in __schedule

Status: upstream: reported syz repro on 2025/06/24 13:44
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+36ed63974f7313c022a9@syzkaller.appspotmail.com
First crash: 28d, last: 21d
Bug presence (1)
Date Name Commit Repro Result
2025/06/25 upstream (ToT) 7595b66ae9de C [report] KASAN: out-of-bounds Write in end_buffer_read_sync
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KMSAN: uninit-value in __schedule (4) reiserfs sctp 17 C error 4 690d 686d 0/29 auto-obsoleted due to no activity on 2023/12/10 17:35
linux-4.19 KASAN: use-after-free Read in __schedule 19 1 1604d 1604d 0/1 auto-closed as invalid on 2021/06/29 13:25
upstream KMSAN: uninit-value in __schedule (5) netfilter 19 547 28d 468d 0/29 upstream: reported on 2024/04/10 09:12
linux-4.19 KASAN: use-after-free Read in __schedule (2) 19 1 1280d 1280d 0/1 auto-closed as invalid on 2022/05/18 22:28
android-54 BUG: unable to handle kernel paging request in __schedule 8 C 12 1608d 1765d 0/2 auto-obsoleted due to no activity on 2023/04/17 21:57
upstream KMSAN: uninit-value in __schedule (3) net trace 7 2 887d 891d 0/29 auto-obsoleted due to no activity on 2023/05/17 02:32
upstream KMSAN: uninit-value in __schedule (2) kernel 7 1 1061d 1061d 0/29 auto-obsoleted due to no activity on 2022/11/24 18:35
upstream WARNING: locking bug in __schedule mm 4 1943 119d 409d 0/29 auto-obsoleted due to no activity on 2025/06/02 23:27
upstream BUG: unable to handle kernel paging request in __schedule kernel 8 2 2787d 2782d 3/29 fixed on 2018/01/03 02:35

Sample crash report:
BUG: unable to handle page fault for address: ffffff888018ea20
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD c691067 P4D c691067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4513 Comm: syz.0.16 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:end_of_stack include/linux/sched/task_stack.h:32 [inline]
RIP: 0010:schedule_debug kernel/sched/core.c:5802 [inline]
RIP: 0010:__schedule+0x124/0x40d0 kernel/sched/core.c:6454
Code: 5c 24 40 4c 8b 23 49 8d 5c 24 20 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 dc 6e ba f7 <48> 8b 1b 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c
RSP: 0018:ffffc900037676c0 EFLAGS: 00010246
RAX: 1ffffff110031d44 RBX: ffffff888018ea20 RCX: dffffc0000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900037677f0
RBP: ffffc90003767850 R08: dffffc0000000000 R09: ffffc900037677e0
R10: fffff520006ecefe R11: 1ffff920006ecefc R12: ffffff888018ea00
R13: ffff8880b8f00000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f2f7f77c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffff888018ea20 CR3: 0000000078358000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x97/0x280 kernel/time/timer.c:1941
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x2b9/0x590 kernel/sched/completion.c:138
 rdmsr_safe_on_cpu+0x139/0x210 arch/x86/lib/msr-smp.c:183
 msr_read+0x10a/0x1b0 arch/x86/kernel/msr.c:67
 vfs_read+0x2c0/0x920 fs/read_write.c:468
 ksys_read+0x143/0x240 fs/read_write.c:613
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2f7e98e929
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:00007f2f7f77c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f2f7ebb5fa0 RCX: 00007f2f7e98e929
RDX: 0000000000018ff8 RSI: 0000200000019680 RDI: 0000000000000005
RBP: 00007f2f7ea10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2f7ebb5fa0 R15: 00007ffc87ada948
 </TASK>
Modules linked in:
CR2: ffffff888018ea20
---[ end trace 0000000000000000 ]---
RIP: 0010:end_of_stack include/linux/sched/task_stack.h:32 [inline]
RIP: 0010:schedule_debug kernel/sched/core.c:5802 [inline]
RIP: 0010:__schedule+0x124/0x40d0 kernel/sched/core.c:6454
Code: 5c 24 40 4c 8b 23 49 8d 5c 24 20 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 df e8 dc 6e ba f7 <48> 8b 1b 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c
RSP: 0018:ffffc900037676c0 EFLAGS: 00010246

RAX: 1ffffff110031d44 RBX: ffffff888018ea20 RCX: dffffc0000000000
RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffffc900037677f0
RBP: ffffc90003767850 R08: dffffc0000000000 R09: ffffc900037677e0
R10: fffff520006ecefe R11: 1ffff920006ecefc R12: ffffff888018ea00
R13: ffff8880b8f00000 R14: dffffc0000000000 R15: 0000000000000000
FS:  00007f2f7f77c6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffff888018ea20 CR3: 0000000078358000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	5c                   	pop    %rsp
   1:	24 40                	and    $0x40,%al
   3:	4c 8b 23             	mov    (%rbx),%r12
   6:	49 8d 5c 24 20       	lea    0x20(%r12),%rbx
   b:	48 89 d8             	mov    %rbx,%rax
   e:	48 c1 e8 03          	shr    $0x3,%rax
  12:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  19:	fc ff df
  1c:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
  20:	74 08                	je     0x2a
  22:	48 89 df             	mov    %rbx,%rdi
  25:	e8 dc 6e ba f7       	call   0xf7ba6f06
* 2a:	48 8b 1b             	mov    (%rbx),%rbx <-- trapping instruction
  2d:	48 89 d8             	mov    %rbx,%rax
  30:	48 c1 e8 03          	shr    $0x3,%rax
  34:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  3b:	fc ff df
  3e:	80                   	.byte 0x80
  3f:	3c                   	.byte 0x3c

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 15:07 linux-6.1.y 58485ff1a74f e2f27c35 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan BUG: unable to handle kernel paging request in __schedule
2025/07/01 01:50 linux-6.1.y 7e69c33e4858 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Write in __schedule
2025/06/24 13:44 linux-6.1.y 58485ff1a74f e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan KASAN: slab-out-of-bounds Write in __schedule
2025/07/01 02:02 linux-6.1.y 7e69c33e4858 6e83b42d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan BUG: unable to handle kernel paging request in __schedule
* Struck through repros no longer work on HEAD.