kernel BUG in dump_page

Status: upstream: reported on 2026/08/26 16:27
Reported-by: syzbot+04fe83c6cc8991155d94@syzkaller.appspotmail.com
First crash: 4d00h, last: 4d00h

Sample crash report:
 kernel_clone+0x24b/0x900 kernel/fork.c:2765
 __do_sys_clone kernel/fork.c:2906 [inline]
 __se_sys_clone kernel/fork.c:2890 [inline]
 __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2890
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:848!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5076 Comm: syz.4.215 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:folio_entire_mapcount include/linux/mm.h:848 [inline]
RIP: 0010:__dump_page mm/debug.c:99 [inline]
RIP: 0010:dump_page+0xc9c/0x1290 mm/debug.c:131
Code: 81 e5 00 00 01 00 0f 85 d2 03 00 00 e8 fd c7 c4 ff e9 1d 04 00 00 e8 f3 c7 c4 ff 4c 89 ff 48 c7 c6 a0 71 96 8a e8 64 f3 ff ff <0f> 0b 48 89 de 48 81 e6 ff 0f 00 00 31 ff e8 b1 cb c4 ff 48 89 d8
RSP: 0018:ffffc9000d707628 EFLAGS: 00010246
RAX: aa0b0df19b7bf500 RBX: ffffea0001204000 RCX: aa0b0df19b7bf500
RDX: 0000000000000009 RSI: ffffffff8a8c29a0 RDI: ffffffff8adf6120
RBP: dffffc0000000000 R08: ffffffff8e2110ef R09: 1ffffffff1c4221d
R10: dffffc0000000000 R11: fffffbfff1c4221e R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffea0001204000
FS:  00007f6ae56a76c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557fc7ae74b0 CR3: 000000007d17a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 set_migratetype_isolate+0x14af/0x16c0 mm/page_isolation.c:200
 isolate_single_pageblock+0x268/0x1520 mm/page_isolation.c:337
 start_isolate_page_range+0x44/0x280 mm/page_isolation.c:541
 offline_pages+0x39e/0x2bb0 mm/memory_hotplug.c:1855
 memory_block_offline drivers/base/memory.c:250 [inline]
 memory_block_action drivers/base/memory.c:283 [inline]
 memory_block_change_state+0x3b0/0x620 drivers/base/memory.c:305
 device_offline+0x259/0x3a0 drivers/base/core.c:4231
 state_store+0x95/0x170 drivers/base/memory.c:366
 kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
 call_write_iter include/linux/fs.h:2271 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x482/0x9a0 fs/read_write.c:584
 ksys_write+0x14d/0x260 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6ae479e0d9
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:00007f6ae56a7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6ae4a25fa0 RCX: 00007f6ae479e0d9
RDX: 0000000000000007 RSI: 0000200000000200 RDI: 0000000000000003
RBP: 00007f6ae4835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6ae4a26038 R14: 00007f6ae4a25fa0 R15: 00007ffe1e911498
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:folio_entire_mapcount include/linux/mm.h:848 [inline]
RIP: 0010:__dump_page mm/debug.c:99 [inline]
RIP: 0010:dump_page+0xc9c/0x1290 mm/debug.c:131
Code: 81 e5 00 00 01 00 0f 85 d2 03 00 00 e8 fd c7 c4 ff e9 1d 04 00 00 e8 f3 c7 c4 ff 4c 89 ff 48 c7 c6 a0 71 96 8a e8 64 f3 ff ff <0f> 0b 48 89 de 48 81 e6 ff 0f 00 00 31 ff e8 b1 cb c4 ff 48 89 d8
RSP: 0018:ffffc9000d707628 EFLAGS: 00010246
RAX: aa0b0df19b7bf500 RBX: ffffea0001204000 RCX: aa0b0df19b7bf500
RDX: 0000000000000009 RSI: ffffffff8a8c29a0 RDI: ffffffff8adf6120
RBP: dffffc0000000000 R08: ffffffff8e2110ef R09: 1ffffffff1c4221d
R10: dffffc0000000000 R11: fffffbfff1c4221e R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffffea0001204000
FS:  00007f6ae56a76c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5f31bef2f8 CR3: 000000007d17a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/26 16:26 linux-6.1.y 05208478041c a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan kernel BUG in dump_page
* Struck through repros no longer work on HEAD.