WARNING in shrink_one

Status: upstream: reported on 2026/10/19 19:40
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+54f6a8926b40a171f2c8@syzkaller.appspotmail.com
First crash: 17h30m, last: 17h30m
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Title Replies (including bot) Last reply
[syzbot] [mm?] WARNING in shrink_one 3 (4) 2026/10/20 01:25

Sample crash report:
------------[ cut here ]------------
current->flags & PF_MEMALLOC
WARNING: mm/page_alloc.c:4816 at __alloc_pages_slowpath mm/page_alloc.c:4816 [inline], CPU#3: syz-executor/5706
WARNING: mm/page_alloc.c:4816 at __alloc_frozen_pages_noprof+0x1eac/0x3300 mm/page_alloc.c:5449, CPU#3: syz-executor/5706
Modules linked in:

CPU: 3 UID: 0 PID: 5706 Comm: syz-executor Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__alloc_pages_slowpath mm/page_alloc.c:4816 [inline]
RIP: 0010:__alloc_frozen_pages_noprof+0x1eac/0x3300 mm/page_alloc.c:5449
Code: 38 d0 7c 08 84 d2 0f 85 de 12 00 00 65 48 8b 05 c2 6c 1c 13 c7 84 24 94 00 00 00 00 80 00 00 f6 40 2d 08 0f 84 ba e7 ff ff 90 <0f> 0b 90 e9 b1 e7 ff ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03
RSP: 0000:ffffc900045465e8 EFLAGS: 00010202

RAX: ffff88802a07a580 RBX: 0000000000000000 RCX: 1ffff1100fffad29
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88803fffd938
RBP: ffff88802a07a5ac R08: 0000000000008000 R09: 0000000000000001
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000048c40
R13: ffff88803fffb900 R14: 0000000000000000 R15: 1ffff920008a8cd7
FS:  0000000000000000(0000) GS:ffff888095a4a000(0063) knlGS:00000000567714c0
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7159f10 CR3: 00000000265ed000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 00000000000f000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 alloc_pages_mpol+0x201/0x550 mm/mempolicy.c:2486
 alloc_pages_noprof mm/mempolicy.c:2577 [inline]
 folio_alloc_noprof+0x22/0x250 mm/mempolicy.c:2587
 filemap_alloc_folio_noprof.part.0+0x3db/0x440 mm/filemap.c:1019
 shrink_one+0x398/0x850 mm/vmscan.c:5119
 shrink_many mm/vmscan.c:5180 [inline]
 lru_gen_shrink_node mm/vmscan.c:5258 [inline]
 shrink_node+0x2b20/0x4320 mm/vmscan.c:6247
 shrink_zones mm/vmscan.c:6503 [inline]
 do_try_to_free_pages+0x33e/0x16d0 mm/vmscan.c:6565
 try_to_free_pages+0x2a0/0x740 mm/vmscan.c:6804
 __perform_reclaim mm/page_alloc.c:4451 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:4478 [inline]
 __alloc_pages_slowpath mm/page_alloc.c:4939 [inline]
 __alloc_frozen_pages_noprof+0xf8a/0x3300 mm/page_alloc.c:5449
 alloc_pages_mpol+0x201/0x550 mm/mempolicy.c:2486
 alloc_pages_noprof mm/mempolicy.c:2577 [inline]
 folio_alloc_noprof+0x22/0x250 mm/mempolicy.c:2587
 filemap_alloc_folio_noprof.part.0+0x3db/0x440 mm/filemap.c:1019
 filemap_alloc_folio_noprof mm/filemap.c:2033 [inline]
 __filemap_get_folio_mpol+0x653/0x1280 mm/filemap.c:2018
 __filemap_get_folio include/linux/pagemap.h:761 [inline]
 filemap_fault+0x879/0x3130 mm/filemap.c:3607
 __do_fault+0x10b/0x440 mm/memory.c:5565
 do_read_fault mm/memory.c:6000 [inline]
 do_fault+0xb3f/0x1830 mm/memory.c:6134
 do_pte_missing mm/memory.c:4700 [inline]
 handle_pte_fault mm/memory.c:6558 [inline]
 __handle_mm_fault+0x150b/0x2f60 mm/memory.c:6707
 handle_mm_fault+0x363/0xa20 mm/memory.c:6876
 do_user_addr_fault+0x59c/0x12f0 arch/x86/mm/fault.c:1343
 handle_page_fault arch/x86/mm/fault.c:1483 [inline]
 exc_page_fault+0x6f/0xd0 arch/x86/mm/fault.c:1536
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0023:0xf7159f10
Code: Unable to access opcode bytes at 0xf7159ee6.
RSP: 002b:00000000ffdf10b0 EFLAGS: 00010283
RAX: 0000000000000051 RBX: 00000000f73ebff4 RCX: 0000000000000050
RDX: 0000000056792cf8 RSI: 0000000056792748 RDI: 00000000f73f2760
RBP: 00000000000005b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/19 08:29 upstream a0ff06b3a7bd 432c0077 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in shrink_one
* Struck through repros no longer work on HEAD.