[moderation] [kernel?] BUG: unable to handle kernel NULL pointer dereference in __put_partials (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 083fc6d7fa0d Merge tag 'sched-urgent-2025-09-26' of git://..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12b29f12580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f5b21423ca3f0a96
dashboard link: https://syzkaller.appspot.com/bug?extid=d778e68656f0deba4fde
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
CC: [b...@alien8.de dave....@linux.intel.com h...@zytor.com linux-...@vger.kernel.org mi...@redhat.com tg...@linutronix.de x...@kernel.org]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/198ae77e2418/disk-083fc6d7.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3d3f065fd75c/vmlinux-083fc6d7.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e65812e9d7b0/bzImage-083fc6d7.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d778e6...@syzkaller.appspotmail.com

BUG: kernel NULL pointer dereference, address: 0000000000000001
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 8000000057273067 P4D 8000000057273067 PUD 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 31 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: slub_flushwq flush_cpu_slab
RIP: 0010:PagePoisoned include/linux/page-flags.h:335 [inline]
RIP: 0010:page_to_nid include/linux/mm.h:1516 [inline]
RIP: 0010:folio_nid include/linux/mm.h:1522 [inline]
RIP: 0010:slab_nid mm/slab.h:177 [inline]
RIP: 0010:__put_partials+0x28/0x1a0 mm/slub.c:3197
Code: 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 48 85 f6 0f 84 4a 01 00 00 49 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 45 31 e4 <49> 8b 07 48 83 f8 ff 0f 84 40 01 00 00 49 8b 5f 10 48 c1 e8 3a 4d
RSP: 0018:ffffc90000a5fa38 EFLAGS: 00010246
RAX: c90b4a7c926c3000 RBX: ffffffff818b5a7f RCX: 0000000000000000
RDX: ffff88801cac5d80 RSI: 0000000000000001 RDI: ffff888035b64640
RBP: ffffc90000a5fc70 R08: ffffffff8f1d6237 R09: 1ffffffff1e3ac46
R10: dffffc0000000000 R11: fffffbfff1e3ac47 R12: 0000000000000000
R13: ffff88801c6ce318 R14: ffff888035b64640 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000001 CR3: 000000003a9aa000 CR4: 00000000003526f0
Call Trace:
<TASK>
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
CR2: 0000000000000001
---[ end trace 0000000000000000 ]---
RIP: 0010:PagePoisoned include/linux/page-flags.h:335 [inline]
RIP: 0010:page_to_nid include/linux/mm.h:1516 [inline]
RIP: 0010:folio_nid include/linux/mm.h:1522 [inline]
RIP: 0010:slab_nid mm/slab.h:177 [inline]
RIP: 0010:__put_partials+0x28/0x1a0 mm/slub.c:3197
Code: 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 10 48 85 f6 0f 84 4a 01 00 00 49 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 45 31 e4 <49> 8b 07 48 83 f8 ff 0f 84 40 01 00 00 49 8b 5f 10 48 c1 e8 3a 4d
RSP: 0018:ffffc90000a5fa38 EFLAGS: 00010246
RAX: c90b4a7c926c3000 RBX: ffffffff818b5a7f RCX: 0000000000000000
RDX: ffff88801cac5d80 RSI: 0000000000000001 RDI: ffff888035b64640
RBP: ffffc90000a5fc70 R08: ffffffff8f1d6237 R09: 1ffffffff1e3ac46
R10: dffffc0000000000 R11: fffffbfff1e3ac47 R12: 0000000000000000
R13: ffff88801c6ce318 R14: ffff888035b64640 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000001 CR3: 000000003a9aa000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 55 push %rbp
3: 41 57 push %r15
5: 41 56 push %r14
7: 41 55 push %r13
9: 41 54 push %r12
b: 53 push %rbx
c: 48 83 ec 10 sub $0x10,%rsp
10: 48 85 f6 test %rsi,%rsi
13: 0f 84 4a 01 00 00 je 0x163
19: 49 89 f7 mov %rsi,%r15
1c: 49 89 fe mov %rdi,%r14
1f: 48 c7 04 24 00 00 00 movq $0x0,(%rsp)
26: 00
27: 45 31 e4 xor %r12d,%r12d
* 2a: 49 8b 07 mov (%r15),%rax <-- trapping instruction
2d: 48 83 f8 ff cmp $0xffffffffffffffff,%rax
31: 0f 84 40 01 00 00 je 0x177
37: 49 8b 5f 10 mov 0x10(%r15),%rbx
3b: 48 c1 e8 3a shr $0x3a,%rax
3f: 4d rex.WRB


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