syzbot

INFO: task kworker/1:0:23 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:24152 pid:23    ppid:2      flags:0x00004000
Workqueue: gfs2_recovery gfs2_recover_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 io_schedule+0x80/0xd0 kernel/sched/core.c:9023
 folio_wait_bit_common+0x714/0xfa0 mm/filemap.c:1329
 folio_wait_locked include/linux/pagemap.h:1149 [inline]
 gfs2_jhead_process_page+0x17e/0x720 fs/gfs2/lops.c:477
 gfs2_find_jhead+0xbe5/0xd20 fs/gfs2/lops.c:594
 gfs2_recover_func+0x708/0x1d20 fs/gfs2/recovery.c:460
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
INFO: task syz.0.17:5934 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17        state:D stack:24624 pid:5934  ppid:5893   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:199
 __wait_on_bit+0xac/0x2d0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x13c/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_recover_journal+0xda/0x130 fs/gfs2/recovery.c:577
 init_journal+0x17d6/0x2330 fs/gfs2/ops_fstype.c:833
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:886
 gfs2_fill_super+0x17bc/0x1f30 fs/gfs2/ops_fstype.c:1266
 get_tree_bdev+0x3f3/0x520 fs/super.c:1591
 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1344
 vfs_get_tree+0x8c/0x280 fs/super.c:1764
 do_new_mount+0x24b/0xa40 fs/namespace.c:3386
 do_mount fs/namespace.c:3726 [inline]
 __do_sys_mount fs/namespace.c:3935 [inline]
 __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f863e99e04a
RSP: 002b:00007ffcc2ff6e28 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcc2ff6eb0 RCX: 00007f863e99e04a
RDX: 0000200000037f40 RSI: 00002000000008c0 RDI: 00007ffcc2ff6e70
RBP: 0000200000037f40 R08: 00007ffcc2ff6eb0 R09: 0000000001010084
R10: 0000000001010084 R11: 0000000000000246 R12: 00002000000008c0
R13: 00007ffcc2ff6e70 R14: 0000000000037f45 R15: 0000200000000480
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/1:0/23:
 #0: ffff88814005ad38 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #0: ffff88814005ad38 ((wq_completion)gfs2_recovery){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
 #1: ffffc900001d7d00 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline]
 #1: ffffc900001d7d00 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730
1 lock held by khungtaskd/29:
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5528:
 #0: ffff88802d1910a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by syz.0.17/5934:
 #0: ffff888078d2e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888078d2e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888078d2e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: get_tree_bdev+0x353/0x520 fs/super.c:1589
2 locks held by syz.1.216/6367:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf3d/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4416 Comm: kworker/u4:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:jhash2 include/linux/jhash.h:127 [inline]
RIP: 0010:hash_stack lib/stackdepot.c:322 [inline]
RIP: 0010:__stack_depot_save+0x5a/0x630 lib/stackdepot.c:382
Code: ab 00 13 00 0f 85 41 05 00 00 43 8d 34 36 46 8d 24 f5 7b 71 f5 75 83 fe 04 0f 82 83 00 00 00 44 89 e0 44 89 e1 48 89 da 03 0a <03> 42 04 44 03 62 08 44 89 e7 c1 c7 04 44 29 e1 31 cf 41 01 c4 29
RSP: 0018:ffffc9000e8673e8 EFLAGS: 00000a07
RAX: 000000009709c1a7 RBX: ffffc9000e867480 RCX: 000000006df2f96a
RDX: ffffc9000e8674e0 RSI: 0000000000000008 RDI: 000000001e00ef33
RBP: 00000000001d2820 R08: 000000008ccf744c R09: 000000002838854f
R10: 0000000000000004 R11: 0000000000000000 R12: 000000008ec33965
R13: 1ffff11005f7146e R14: 0000000000000010 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa83abfe000 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 save_stack+0x133/0x230 mm/page_owner.c:129
 __set_page_owner+0x1d/0x60 mm/page_owner.c:192
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581
 prep_new_page mm/page_alloc.c:1588 [inline]
 get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500
 alloc_slab_page+0x5d/0x160 mm/slub.c:1881
 allocate_slab mm/slub.c:2028 [inline]
 new_slab+0x87/0x2d0 mm/slub.c:2081
 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253
 __slab_alloc mm/slub.c:3339 [inline]
 __slab_alloc_node mm/slub.c:3392 [inline]
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534
 __do_kmalloc_node mm/slab_common.c:1006 [inline]
 __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x293/0xb00 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>