syzbot

INFO: task kworker/0:9:4331 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:9     state:D stack:23832 pid:4331  ppid:2      flags:0x00004000
Workqueue: gfs_recovery gfs2_recover_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8798
 folio_wait_bit_common+0x70a/0xfa0 mm/filemap.c:1324
 folio_wait_locked include/linux/pagemap.h:1059 [inline]
 gfs2_jhead_process_page+0x17a/0x800 fs/gfs2/lops.c:476
 gfs2_find_jhead+0xba2/0xd00 fs/gfs2/lops.c:594
 gfs2_recover_func+0x6d2/0x1ca0 fs/gfs2/recovery.c:460
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
INFO: task syz.0.17:4431 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:24784 pid:4431  ppid:4387   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 bit_wait+0xd/0xc0 kernel/sched/wait_bit.c:199
 __wait_on_bit+0xa8/0x2d0 kernel/sched/wait_bit.c:49
 out_of_line_wait_on_bit+0x138/0x190 kernel/sched/wait_bit.c:64
 wait_on_bit include/linux/wait_bit.h:76 [inline]
 gfs2_recover_journal+0xd6/0x130 fs/gfs2/recovery.c:577
 init_journal+0x17fc/0x23e0 fs/gfs2/ops_fstype.c:835
 init_inodes+0xdb/0x320 fs/gfs2/ops_fstype.c:889
 gfs2_fill_super+0x1749/0x1fb0 fs/gfs2/ops_fstype.c:1246
 get_tree_bdev+0x3f1/0x610 fs/super.c:1366
 gfs2_get_tree+0x4d/0x1e0 fs/gfs2/ops_fstype.c:1327
 vfs_get_tree+0x88/0x270 fs/super.c:1573
 do_new_mount+0x24a/0xa40 fs/namespace.c:3078
 do_mount fs/namespace.c:3421 [inline]
 __do_sys_mount fs/namespace.c:3629 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e7519e04a
RSP: 002b:00007ffc20c44a18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffc20c44aa0 RCX: 00007f4e7519e04a
RDX: 0000200000037f40 RSI: 00002000000008c0 RDI: 00007ffc20c44a60
RBP: 0000200000037f40 R08: 00007ffc20c44aa0 R09: 0000000001010084
R10: 0000000001010084 R11: 0000000000000246 R12: 00002000000008c0
R13: 00007ffc20c44a60 R14: 0000000000037f45 R15: 0000200000000480
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8cb2df70 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8cb2e790 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
 #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8cb2d5e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4022:
 #0: ffff88814d2c5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x429/0x1390 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:9/4331:
 #0: ffff88801af99938 ((wq_completion)gfs_recovery){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
 #1: ffffc90003f77d00 ((work_completion)(&jd->jd_work)){+.+.}-{0:0}, at: process_one_work+0x7b0/0x1160 kernel/workqueue.c:2267
2 locks held by kworker/u4:5/4377:
1 lock held by syz.0.17/4431:
 #0: ffff88807a7560e0 (&type->s_umount_key#52/1){+.+.}-{3:3}, at: alloc_super+0x1fa/0x930 fs/super.c:228
2 locks held by syz.1.215/4659:
2 locks held by dhcpcd/4660:
 #0: 
ffff888147b20130
 (
sk_lock-AF_PACKET
){+.+.}-{0:0}
, at: lock_sock include/net/sock.h:1805 [inline]
, at: packet_do_bind+0x32/0xce0 net/packet/af_packet.c:3249
 #1: 
ffffffff8cb332b8
 (rcu_state.exp_mutex
){+.+.}-{3:3}
, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
, at: synchronize_rcu_expedited+0x2ec/0x890 kernel/rcu/tree_exp.h:962

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

NMI backtrace for cpu 1
CPU: 1 PID: 28 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+0x188/0x24e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xeee/0xf30 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 11 Comm: kworker/u4:1 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:__orc_find arch/x86/kernel/unwind_orc.c:50 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x132e/0x20b0 arch/x86/kernel/unwind_orc.c:448
Code: 00 c6 05 56 5b d2 0c 01 48 c7 c7 40 83 89 8a 48 8b 74 24 68 e8 75 94 e9 08 e9 7f 05 00 00 49 89 f7 49 89 f5 4c 89 e0 4c 29 e8 <48> 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4d 8d 74 45
RSP: 0018:ffffc900001075b0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffffc90000107688 RCX: ffffffff96c00100
RDX: ffffffff8ef1ef72 RSI: ffffffff8e66b0ec RDI: 0000000000000001
RBP: ffffffff86138c8e R08: 0000000000000001 R09: 0000000000000005
R10: dffffc0000000000 R11: fffff52000020edd R12: ffffffff8e66b0ec
R13: ffffffff8e66b0ec R14: 000000000005138c R15: ffffffff8e66b0ec
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f75987e2000 CR3: 0000000072b7a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 __kasan_slab_alloc+0x6b/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737
 slab_alloc_node mm/slub.c:3359 [inline]
 kmem_cache_alloc_node+0x14d/0x320 mm/slub.c:3404
 __alloc_skb+0xfc/0x7e0 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1303 [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+0x28f/0xaf0 drivers/net/netdevsim/dev.c:851
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>