BUG: unable to handle kernel paging request in write_comp_data

Status: upstream: reported C repro on 2026/08/02 04:52
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+237f670105a254a230d4@syzkaller.appspotmail.com
First crash: 66d, last: now
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
b5fb3d3b repro-c Reproduced: ✅ ❓ BUG: unable to handle kernel paging request in write_comp_data 2026/09/14 21:04 2026/09/14 21:04 2026/09/14 21:57 81a27d1a
9f28d2e2 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ BUG: unable to handle kernel paging request in write_comp_data 2026/07/31 00:00 2026/07/31 00:00 2026/07/31 00:54 aaffb173
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] kcov: add a missing bound check in write_comp_data() 1 (1) 2026/09/15 03:33
[syzbot] [kernel?] BUG: unable to handle kernel paging request in write_comp_data 1 (4) 2026/09/15 03:24
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2026/09/15 02:06 14m eadavis@sina.com patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 704340f1cd0d OK job log log
2026/09/14 21:58 12m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 704340f1cd0dcef829eb62f5b48ae95a2ce17bdf report job log log

Sample crash report:
BUG: unable to handle page fault for address: ffffc90003792fe8
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1c000067 P4D 1c000067 PUD 1d695067 PMD 25aa1067 PTE 0
Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 6034 Comm: syz-executor404 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:write_comp_data+0x7c/0xa0 kernel/kcov.c:263
Code: 00 8b bf 14 17 00 00 48 8b 30 48 c1 e7 03 4c 8d 1c b5 00 00 00 00 4a 8d 14 dd 28 00 00 00 48 39 d7 72 1b 48 83 c6 01 48 89 30 <4c> 89 44 10 e0 4c 89 4c 10 e8 4c 89 54 10 f0 4a 89 4c d8 20 e9 9b
RSP: 0018:ffffc900016cfec0 EFLAGS: 00010257
RAX: ffffc90003793000 RBX: 0000000000000000 RCX: ffffffff824af562
RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000002000
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: fffffffffffffffc R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  000055556039d400(0000) GS:ffff8880d5d59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90003792fe8 CR3: 0000000033822000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __do_sys_rseq kernel/rseq.c:549 [inline]
 __se_sys_rseq kernel/rseq.c:547 [inline]
 __x64_sys_rseq+0xc2/0x2e0 kernel/rseq.c:547
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f6e875649
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffe975f1b8 EFLAGS: 00000246 ORIG_RAX: 000000000000014e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4f6e875649
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4f6e846000 R08: 0000000000000000 R09: 00000000000a8ca8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffe975f2e8
R13: 0000000000000002 R14: 00007f4f6e8f8cc0 R15: 0000000000000002
 </TASK>
Modules linked in:
CR2: ffffc90003792fe8
---[ end trace 0000000000000000 ]---
RIP: 0010:write_comp_data+0x7c/0xa0 kernel/kcov.c:263
Code: 00 8b bf 14 17 00 00 48 8b 30 48 c1 e7 03 4c 8d 1c b5 00 00 00 00 4a 8d 14 dd 28 00 00 00 48 39 d7 72 1b 48 83 c6 01 48 89 30 <4c> 89 44 10 e0 4c 89 4c 10 e8 4c 89 54 10 f0 4a 89 4c d8 20 e9 9b
RSP: 0018:ffffc900016cfec0 EFLAGS: 00010257
RAX: ffffc90003793000 RBX: 0000000000000000 RCX: ffffffff824af562
RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000002000
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: fffffffffffffffc R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  000055556039d400(0000) GS:ffff8880d5d59000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90003792fe8 CR3: 0000000033822000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	00 8b bf 14 17 00    	add    %cl,0x1714bf(%rbx)
   6:	00 48 8b             	add    %cl,-0x75(%rax)
   9:	30 48 c1             	xor    %cl,-0x3f(%rax)
   c:	e7 03                	out    %eax,$0x3
   e:	4c 8d 1c b5 00 00 00 	lea    0x0(,%rsi,4),%r11
  15:	00
  16:	4a 8d 14 dd 28 00 00 	lea    0x28(,%r11,8),%rdx
  1d:	00
  1e:	48 39 d7             	cmp    %rdx,%rdi
  21:	72 1b                	jb     0x3e
  23:	48 83 c6 01          	add    $0x1,%rsi
  27:	48 89 30             	mov    %rsi,(%rax)
* 2a:	4c 89 44 10 e0       	mov    %r8,-0x20(%rax,%rdx,1) <-- trapping instruction
  2f:	4c 89 4c 10 e8       	mov    %r9,-0x18(%rax,%rdx,1)
  34:	4c 89 54 10 f0       	mov    %r10,-0x10(%rax,%rdx,1)
  39:	4a 89 4c d8 20       	mov    %rcx,0x20(%rax,%r11,8)
  3e:	e9                   	.byte 0xe9
  3f:	9b                   	fwait

Crashes (578):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/14 22:11 git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 704340f1cd0d 924033e8 .config console log report C ci-qemu-upstream BUG: unable to handle kernel paging request in write_comp_data
2026/10/03 06:00 upstream ff47652a4b66 57bbd979 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/02 19:04 upstream ce1e0223d8ad 1065c8fa .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/02 16:27 upstream ce1e0223d8ad 1065c8fa .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/02 06:58 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/02 05:41 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/02 01:04 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/02 01:02 upstream d24e8ac715de 6d32eb1f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/01 15:12 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/01 14:10 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/01 12:35 upstream 551c722f4080 38f7f0d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/01 03:58 upstream 551c722f4080 15fb8e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/01 01:10 upstream 551c722f4080 15fb8e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/10/01 00:29 upstream 551c722f4080 15fb8e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/30 16:07 upstream 551c722f4080 7808aef4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/29 04:21 upstream 72d3fcf802c4 58f15308 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/29 00:51 upstream 72d3fcf802c4 58f15308 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/28 16:33 upstream 72d3fcf802c4 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/28 16:30 upstream 72d3fcf802c4 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/28 07:42 upstream d266640c6c76 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/28 05:27 upstream d266640c6c76 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/28 03:51 upstream d266640c6c76 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/27 13:47 upstream fd179f8a05be a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/27 12:37 upstream fd179f8a05be a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/27 04:32 upstream 6812ce4e4379 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/27 02:20 upstream 6812ce4e4379 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/26 23:58 upstream 6812ce4e4379 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/26 14:19 upstream f14572c203d5 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/26 12:00 upstream f14572c203d5 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/26 09:27 upstream f14572c203d5 a3c7249d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/25 20:54 upstream 165768bb7026 f281d9d2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/24 17:18 upstream 62f4c998b297 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/24 16:14 upstream 62f4c998b297 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/24 14:45 upstream 62f4c998b297 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/24 13:41 upstream 62f4c998b297 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/24 12:37 upstream 62f4c998b297 3c3cdf19 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/23 11:23 upstream fe2ec83746e5 abce1216 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/23 03:35 upstream fe2ec83746e5 3e2106e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/23 03:35 upstream fe2ec83746e5 3e2106e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/22 02:12 upstream 93f51579e7df a8efa948 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/20 21:59 upstream 40288c9206c1 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/20 20:10 upstream 40288c9206c1 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/20 12:49 upstream 40288c9206c1 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/20 11:41 upstream 40288c9206c1 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/09/14 19:58 upstream 704340f1cd0d 924033e8 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/08/01 06:30 upstream a2cf4ef33184 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/07/30 20:56 upstream 11028ab62899 abc81b93 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
2026/07/29 04:47 upstream 3b5f4b83c4ab 4a865b71 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in write_comp_data
* Struck through repros no longer work on HEAD.