INFO: task kworker/u8:11:26400 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11   state:D stack:19792 pid:26400 tgid:26400 ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 afs_cell_purge+0x3d9/0x540 fs/afs/cell.c:894
 afs_net_exit+0x50/0x100 fs/afs/main.c:147
 ops_exit_list net/core/net_namespace.c:198 [inline]
 ops_undo_list+0x49a/0x990 net/core/net_namespace.c:251
 cleanup_net+0x4c5/0x800 net/core/net_namespace.c:682
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6211 Comm: syz.8.7991 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:shmem_alloc_and_add_folio+0x7c4/0xf60 mm/shmem.c:1958
Code: 49 0f ba 6d 00 11 44 8b 7c 24 10 41 81 e7 e0 ec 0b 01 0f 1f 44 00 00 4c 89 ef 48 8b 74 24 68 44 89 fa e8 6f 6d 2a 00 41 89 c6 <31> ff 89 c6 e8 33 b2 be ff 44 89 74 24 18 45 85 f6 74 50 48 8d b4
RSP: 0018:ffffc9000bad6880 EFLAGS: 00000287
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 856b34ffce737e00
RDX: 0000000000000000 RSI: ffffffff8be33660 RDI: ffff8880222bbc00
RBP: ffffc9000bad69d0 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f47067 R12: ffffea0001002748
R13: ffffea0001002740 R14: 0000000000000000 R15: 0000000000000cc0
FS:  00007f4b563f66c0(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff62f31fb8 CR3: 000000006869f000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597
 shmem_get_folio mm/shmem.c:2703 [inline]
 shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528
 __kernel_write_iter+0x428/0x910 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1296 [inline]
 dump_user_range+0x8a0/0xc90 fs/coredump.c:1370
 elf_core_dump+0x337b/0x3990 fs/binfmt_elf.c:2085
 coredump_write+0x1169/0x1900 fs/coredump.c:1049
 vfs_coredump+0x1daa/0x2a50 fs/coredump.c:1168
 get_signal+0x1109/0x1340 kernel/signal.c:3019
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
 exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7f4b5818ebf1
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffed0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f4b583b5fa0 RCX: 00007f4b5818ebe9
RDX: 0000000000000000 RSI: fffffffffffffed0 RDI: 0000000000008200
RBP: 00007f4b58211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f4b583b6038 R14: 00007f4b583b5fa0 R15: 00007ffe68f08e48
 </TASK>