INFO: task syz.0.16:6723 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.16 state:D stack:28360 pid:6723 tgid:6700 ppid:6629 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:867 [inline] f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 vfs_fallocate+0x6a0/0x830 fs/open.c:338 ioctl_preallocate fs/ioctl.c:290 [inline] file_ioctl fs/ioctl.c:-1 [inline] do_vfs_ioctl+0x1b8f/0x1eb0 fs/ioctl.c:885 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f580a38e169 RSP: 002b:00007f580b205038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f580a5b6080 RCX: 00007f580a38e169 RDX: 0000200000000000 RSI: 0000000040305828 RDI: 0000000000000004 RBP: 00007f580a410a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f580a5b6080 R15: 00007ffe3722ebc8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5584: #0: ffff88814e3f80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002ffe2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 3 locks held by syz.0.16/6701: 2 locks held by syz.0.16/6723: #0: ffff8880243a0420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff8880243a0420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff888075801c18 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff888075801c18 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 3 locks held by syz.1.17/6799: 2 locks held by syz.1.17/6802: #0: ffff888030014420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888030014420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff8880736b1c18 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff8880736b1c18 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 4 locks held by syz.2.18/6820: 2 locks held by syz.2.18/6823: #0: ffff888079554420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888079554420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff8880736b3fd8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff8880736b3fd8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 4 locks held by syz.3.19/6846: 2 locks held by syz.3.19/6849: #0: ffff888028bbe420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888028bbe420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff8880736b6398 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff8880736b6398 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 3 locks held by syz.4.20/6871: 2 locks held by syz.4.20/6874: #0: ffff888062e70420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888062e70420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff888067540a38 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff888067540a38 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 3 locks held by syz.5.21/6898: 2 locks held by syz.5.21/6901: #0: ffff888063350420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888063350420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff888067542df8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff888067542df8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 4 locks held by syz.6.22/6932: 2 locks held by syz.6.22/6935: #0: ffff888030020420 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff888030020420 (sb_writers#12){.+.+}-{0:0}, at: vfs_fallocate+0x62a/0x830 fs/open.c:337 #1: ffff888075803fd8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff888075803fd8 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}, at: f2fs_fallocate+0x24e/0x990 fs/f2fs/file.c:1940 6 locks held by syz-executor/6937: #0: ffff88807c708420 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3041 [inline] #0: ffff88807c708420 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:680 #1: ffff8880625e5c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffffffff8df74dc8 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_lock include/linux/cgroup.h:369 [inline] #2: ffffffff8df74dc8 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x13c/0x230 kernel/cgroup/cgroup.c:1675 #3: ffffffff8ddd6910 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2478 [inline] #3: ffffffff8ddd6910 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x186/0x600 kernel/cgroup/cgroup.c:2982 #4: ffffffff8df74fb0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2480 [inline] #4: ffffffff8df74fb0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x19c/0x600 kernel/cgroup/cgroup.c:2982 #5: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #5: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f4/0x730 kernel/rcu/tree_exp.h:998 2 locks held by udevd/6956: #0: ffff8880b89399d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:605 #1: ffff8880b8923b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.15.0-rc6-syzkaller-00188-gfee3e843b309 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline] RIP: 0010:lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842 Code: f6 05 ac 91 c9 0d 01 0f 84 d7 01 00 00 83 3d 79 c3 df 0d 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 23 5f 81 00 <83> 3d 5c c3 df 0d 00 0f 84 fa 00 00 00 65 8b 05 3f 6d d4 10 85 c0 RSP: 0018:ffffc90000117a20 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: c20831fd7dfff700 RDX: 0000000000000000 RSI: ffffffff8b1d567f RDI: 1ffffffff1be7b9c RBP: ffffffff8b1d5662 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8b1d5662 R12: 0000000000000002 R13: ffffffff8df3dce0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881260f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f28fd7fae9c CR3: 000000007e6b0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245