syzbot


kernel BUG in __khugepaged_enter

Status: upstream: reported on 2026/02/14 16:40
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+6b554d491efbe066b701@syzkaller.appspotmail.com
First crash: 8d21h, last: 7d13h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] kernel BUG in __khugepaged_enter 4 (5) 2026/02/17 17:30

Sample crash report:
------------[ cut here ]------------
kernel BUG at mm/khugepaged.c:438!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 16472 Comm: syz.3.2372 Tainted: G     U  W    L XTNJ syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [W]=WARN, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:__khugepaged_enter+0x30a/0x380 mm/khugepaged.c:438
Code: 64 7e 8e e8 a8 dc 66 ff e8 93 e6 8d ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 04 6c 04 09 e8 7f e6 8d ff 48 89 df e8 17 33 d9 ff 90 <0f> 0b 48 89 ef e8 dc 51 f8 ff e9 3b fd ff ff e8 f2 52 f8 ff e9 e1
RSP: 0018:ffffc9000e98fba8 EFLAGS: 00010292
RAX: 000000000000031f RBX: ffff888079b24980 RCX: 0000000000000000
RDX: 000000000000031f RSI: ffffffff81e5b2c9 RDI: fffff52001d31f1c
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 0000000008100177
R13: ffff88804adf9510 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f06093436c0(0000) GS:ffff8881245b1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff341d3f52 CR3: 00000000319b0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 khugepaged_enter_vma mm/khugepaged.c:467 [inline]
 khugepaged_enter_vma+0x137/0x2c0 mm/khugepaged.c:461
 do_huge_pmd_anonymous_page+0x1c8/0x1c00 mm/huge_memory.c:1469
 create_huge_pmd mm/memory.c:6102 [inline]
 __handle_mm_fault+0x1e96/0x2b50 mm/memory.c:6376
 handle_mm_fault+0x36d/0xa20 mm/memory.c:6583
 do_user_addr_fault+0x5a3/0x12f0 arch/x86/mm/fault.c:1334
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x87560
Code: Unable to access opcode bytes at 0x87536.
RSP: 002b:000000000000000e EFLAGS: 00010202
RAX: 0000000000000000 RBX: 00007f0608615fa0 RCX: 00007f060839bf79
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0002000020003b4a
RBP: 00007f06084327e0 R08: 0000000000000103 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0608616038 R14: 00007f0608615fa0 R15: 00007ffee482e7a8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__khugepaged_enter+0x30a/0x380 mm/khugepaged.c:438
Code: 64 7e 8e e8 a8 dc 66 ff e8 93 e6 8d ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 04 6c 04 09 e8 7f e6 8d ff 48 89 df e8 17 33 d9 ff 90 <0f> 0b 48 89 ef e8 dc 51 f8 ff e9 3b fd ff ff e8 f2 52 f8 ff e9 e1
RSP: 0018:ffffc9000e98fba8 EFLAGS: 00010292
RAX: 000000000000031f RBX: ffff888079b24980 RCX: 0000000000000000
RDX: 000000000000031f RSI: ffffffff81e5b2c9 RDI: fffff52001d31f1c
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: 0000000008100177
R13: ffff88804adf9510 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f06093436c0(0000) GS:ffff8881245b1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055906703f168 CR3: 00000000319b0000 CR4: 00000000003526f0

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/12 00:59 upstream 1e83ccd5921a 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto kernel BUG in __khugepaged_enter
2026/02/12 00:59 upstream 1e83ccd5921a 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto kernel BUG in __khugepaged_enter
2026/02/12 00:57 upstream 1e83ccd5921a 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto kernel BUG in __khugepaged_enter
2026/02/11 20:00 upstream 192c0159402e 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto kernel BUG in __khugepaged_enter
2026/02/10 16:33 upstream 72c395024dac a076df6f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto kernel BUG in __khugepaged_enter
* Struck through repros no longer work on HEAD.