syzbot


WARNING in shrink_lruvec

Status: upstream: reported on 2025/12/09 12:16
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+90fcab4d88cffed6d0d8@syzkaller.appspotmail.com
First crash: 8d00h, last: 8d00h
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] mm: vmscan: always allow writeback during memcg reclaim 1 (1) 2025/12/13 08:36
[syzbot] [mm?] WARNING in shrink_lruvec 0 (1) 2025/12/09 12:16

Sample crash report:
------------[ cut here ]------------
WARNING: mm/vmscan.c:5049 at lru_gen_shrink_lruvec mm/vmscan.c:5049 [inline], CPU#1: syz.0.6406/391
WARNING: mm/vmscan.c:5049 at shrink_lruvec+0x253b/0x2b50 mm/vmscan.c:5818, CPU#1: syz.0.6406/391
Modules linked in:
CPU: 1 UID: 0 PID: 391 Comm: syz.0.6406 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lru_gen_shrink_lruvec mm/vmscan.c:5049 [inline]
RIP: 0010:shrink_lruvec+0x253b/0x2b50 mm/vmscan.c:5818
Code: 89 de e8 78 78 bf ff 49 8d 46 34 48 89 44 24 38 84 db 0f 84 cf 00 00 00 31 ff b9 02 00 00 00 e9 42 df ff ff e8 06 7e bf ff 90 <0f> 0b 90 e9 45 dd ff ff 48 8b bc 24 98 00 00 00 e8 e0 90 27 00 e9
RSP: 0018:ffffc9000d5def60 EFLAGS: 00010283
RAX: 0000000000001170 RBX: ffffc9000d5df120 RCX: ffffc90014135000
RDX: 0000000000080000 RSI: ffffffff81fe1a6a RDI: 0000000000000001
RBP: ffffc9000d5df2e0 R08: 0000000000000001 R09: 0000000000000030
R10: 0000000000000020 R11: 00000000622d1f49 R12: 0000000000000020
R13: ffff88807cd00d40 R14: ffffc9000d5df628 R15: 1ffff92001abbe0a
FS:  00007f36a7b6f6c0(0000) GS:ffff888124a67000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30008ff8 CR3: 000000005c3e2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 shrink_node_memcgs mm/vmscan.c:6054 [inline]
 shrink_node+0x988/0x3da0 mm/vmscan.c:6095
 shrink_zones mm/vmscan.c:6339 [inline]
 do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6401
 try_to_free_mem_cgroup_pages+0x31b/0x740 mm/vmscan.c:6729
 mem_cgroup_resize_max+0x113/0x2b0 mm/memcontrol-v1.c:1480
 mem_cgroup_write+0x295/0x3a0 mm/memcontrol-v1.c:1662
 cgroup_file_write+0x1ef/0x7a0 kernel/cgroup/cgroup.c:4312
 kernfs_fop_write_iter+0x3af/0x570 fs/kernfs/file.c:352
 iter_file_splice_write+0xa24/0x12b0 fs/splice.c:738
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x192/0x6c0 fs/splice.c:1161
 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1105
 do_splice_direct_actor fs/splice.c:1204 [inline]
 do_splice_direct+0x174/0x240 fs/splice.c:1230
 do_sendfile+0xb06/0xe50 fs/read_write.c:1370
 __do_sys_sendfile64 fs/read_write.c:1431 [inline]
 __se_sys_sendfile64 fs/read_write.c:1417 [inline]
 __x64_sys_sendfile64+0x1d8/0x220 fs/read_write.c:1417
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f36a6d8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f36a7b6f038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f36a6fe5fa0 RCX: 00007f36a6d8f7c9
RDX: 0000000000000000 RSI: 000000000000000b RDI: 000000000000000b
RBP: 00007f36a6e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36a6fe6038 R14: 00007f36a6fe5fa0 R15: 00007ffd83c52c98
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/05 12:07 upstream 2061f18ad76e d1b870e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in shrink_lruvec
* Struck through repros no longer work on HEAD.