INFO: task syz.0.414:7022 blocked for more than 143 seconds. Not tainted 6.11.0-rc6-syzkaller-01330-gbf73478b539b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.414 state:D stack:24672 pid:7022 tgid:7022 ppid:5248 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x1800/0x4a60 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6678 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752 pipe_release+0x4e/0x330 fs/pipe.c:727 __fput+0x24a/0x8a0 fs/file_table.c:422 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5439f7def9 RSP: 002b:00007ffe9109af18 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f543a137a80 RCX: 00007f5439f7def9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f543a137a80 R08: 0000000000000006 R09: 00007ffe9109b20f R10: 00000000005f0d90 R11: 0000000000000246 R12: 00000000000292fb R13: 00007ffe9109b020 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e938320 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6626 1 lock held by dhcpcd/4901: 2 locks held by getty/4990: #0: ffff888034e400a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ac/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by dhcpcd/5019: 1 lock held by syz.0.414/7022: #0: ffff888031833068 (&pipe->mutex){+.+.}-{3:3}, at: pipe_release+0x4e/0x330 fs/pipe.c:727 1 lock held by syz.0.414/7023: #0: ffff888031833068 (&pipe->mutex){+.+.}-{3:3}, at: splice_file_to_pipe+0x2e/0x500 fs/splice.c:1292 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.11.0-rc6-syzkaller-01330-gbf73478b539b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5435 Comm: udevd Not tainted 6.11.0-rc6-syzkaller-01330-gbf73478b539b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline] RIP: 0010:lock_acquire+0x180/0x550 kernel/locking/lockdep.c:5755 Code: 8d bc 24 80 00 00 00 4c 89 fb 48 c1 eb 03 42 80 3c 2b 00 74 08 4c 89 ff e8 3d 06 8b 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c <8f> 84 24 80 00 00 00 42 80 3c 2b 00 74 08 4c 89 ff e8 2a 05 8b 00 RSP: 0018:ffffc90004acf8b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92000959f28 RCX: ffffffff816fcd04 RDX: 0000000000000000 RSI: ffffffff8c608d60 RDI: ffffffff8c608d20 RBP: ffffc90004acfa08 R08: ffffffff9018812f R09: 1ffffffff2031025 R10: dffffc0000000000 R11: fffffbfff2031026 R12: 1ffff92000959f20 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffc90004acf940 FS: 00007efe77e92c80(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7bbfdc6040 CR3: 0000000011e90000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] aa_file_perm+0x154/0xf60 security/apparmor/file.c:585 common_file_perm+0x19c/0x210 security/apparmor/lsm.c:533 security_file_permission+0x6d/0xa0 security/security.c:2722 rw_verify_area+0xbf/0x6b0 fs/read_write.c:377 vfs_read+0x153/0xbc0 fs/read_write.c:467 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7efe77f68b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffea1b0db58 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007efe77f68b6a RDX: 0000000000000080 RSI: 00007ffea1b0dc48 RDI: 0000000000000003 RBP: 00007ffea1b0db98 R08: 0000000000000007 R09: 85b31858f8e009c8 R10: 00000000ffffffff R11: 0000000000000246 R12: 000055a9ee07f5c0 R13: 00007ffea1b0db98 R14: 0000000000000001 R15: 000055a9ee05b910