BUG: unable to handle kernel paging request in write_comp_data

Status: upstream: reported on 2026/08/02 04:52
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+237f670105a254a230d4@syzkaller.appspotmail.com
First crash: 7d10h, last: 19h48m
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ID Workflow Result Correct Bug Created Started Finished Revision
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
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Title Replies (including bot) Last reply
[syzbot] [kernel?] BUG: unable to handle kernel paging request in write_comp_data 0 (1) 2026/08/02 04:52

Sample crash report:
BUG: unable to handle page fault for address: ffffc9001448efe8
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 13fe40067 P4D 13fe40067 PUD 1cae7067 PMD 71727067 PTE 0
Oops: Oops: 0002 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 16748 Comm: syz.1.1552 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:write_comp_data+0x75/0x90 kernel/kcov.c:267
Code: 00 8b bf fc 16 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 bd 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 c3 cc
RSP: 0018:ffffc90004e5fe78 EFLAGS: 00050257
RAX: ffffc9001448f000 RBX: 0000000000000000 RCX: ffffffff82458db5
RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000400000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000002
R10: 0000000000000001 R11: fffffffffffffffc R12: 0000000000000020
R13: 0000000000000000 R14: 00007ffffffff000 R15: 0000000000000001
FS:  00007fe95d7f06c0(0000) GS:ffff888123ddf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc9001448efe8 CR3: 0000000059de4000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rseq_register+0x115/0x350 kernel/rseq.c:460
 __do_sys_rseq kernel/rseq.c:561 [inline]
 __se_sys_rseq kernel/rseq.c:547 [inline]
 __x64_sys_rseq+0x1b8/0x2e0 kernel/rseq.c:547
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe96019e019
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe95d7f0028 EFLAGS: 00000246 ORIG_RAX: 000000000000014e
RAX: ffffffffffffffda RBX: 00007fe960426450 RCX: 00007fe96019e019
RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000000000000
RBP: 00007fe96023500c R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe9604264e8 R14: 00007fe960426450 R15: 00007ffd796d76b8
 </TASK>
Modules linked in:
CR2: ffffc9001448efe8
---[ end trace 0000000000000000 ]---
RIP: 0010:write_comp_data+0x75/0x90 kernel/kcov.c:267
Code: 00 8b bf fc 16 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 bd 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 c3 cc
RSP: 0018:ffffc90004e5fe78 EFLAGS: 00050257
RAX: ffffc9001448f000 RBX: 0000000000000000 RCX: ffffffff82458db5
RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000400000
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000002
R10: 0000000000000001 R11: fffffffffffffffc R12: 0000000000000020
R13: 0000000000000000 R14: 00007ffffffff000 R15: 0000000000000001
FS:  00007fe95d7f06c0(0000) GS:ffff888123ddf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc9001448efe8 CR3: 0000000059de4000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	00 8b bf fc 16 00    	add    %cl,0x16fcbf(%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 bd                	jb     0xffffffe0
  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:	c3                   	ret
  3f:	cc                   	int3

Crashes (49):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/04 19:05 upstream 848acc8ffe1b 3c5eaa21 .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
2026/08/04 17:59 upstream 848acc8ffe1b 3c5eaa21 .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
2026/08/04 09:53 upstream 848acc8ffe1b 9451e17e .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
2026/08/04 08:29 upstream 848acc8ffe1b 9451e17e .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
2026/08/04 06:23 upstream 848acc8ffe1b 9451e17e .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
2026/08/03 22:09 upstream 075b74841bd0 bdd50915 .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
2026/08/03 21:58 upstream 075b74841bd0 bdd50915 .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
2026/08/03 21:58 upstream 075b74841bd0 bdd50915 .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
2026/08/03 21:38 upstream 075b74841bd0 bdd50915 .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
2026/08/03 21:36 upstream 075b74841bd0 bdd50915 .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
2026/08/03 21:35 upstream 075b74841bd0 bdd50915 .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
2026/08/03 21:05 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:55 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:33 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:23 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:19 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:18 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:16 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:14 upstream 075b74841bd0 bdd50915 .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
2026/08/03 20:11 upstream 075b74841bd0 bdd50915 .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
2026/08/03 06:49 upstream bd1dde877520 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
2026/08/03 06:48 upstream bd1dde877520 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
2026/08/03 06:46 upstream bd1dde877520 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
2026/08/03 06:44 upstream bd1dde877520 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
2026/08/03 06:44 upstream bd1dde877520 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
2026/08/03 06:41 upstream bd1dde877520 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
2026/08/02 09:36 upstream 2d2338c93da7 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
2026/08/02 09:24 upstream 2d2338c93da7 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
2026/08/01 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
2026/07/31 20:13 upstream 8ba098e6b6ff db462e94 .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
2026/07/30 20:50 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
2026/07/30 20:45 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
2026/07/30 20:43 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
2026/07/30 20:37 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
2026/07/30 20:35 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 14:37 upstream fc02acf6ac0c 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
2026/07/29 05:35 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
2026/07/29 05:28 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
2026/07/29 05:20 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
2026/07/29 05:16 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
2026/07/29 04:58 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
2026/07/29 04:57 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
2026/07/29 04:56 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
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.