input: syz0 as /devices/virtual/input/input794 input: syz0 as /devices/virtual/input/input795 INFO: task syz-executor.1:31410 blocked for more than 140 seconds. Not tainted 4.14.231-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28904 31410 31405 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:588 [inline] rwsem_down_write_failed+0x343/0x6d0 kernel/locking/rwsem-xadd.c:617 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:105 __down_write arch/x86/include/asm/rwsem.h:126 [inline] down_write+0x4f/0x90 kernel/locking/rwsem.c:56 grab_super+0x55/0x140 fs/super.c:373 sget_userns+0x2b1/0xc10 fs/super.c:504 sget+0xd1/0x110 fs/super.c:572 mount_bdev+0xcd/0x360 fs/super.c:1107 mount_fs+0x92/0x2a0 fs/super.c:1237 vfs_kern_mount.part.0+0x5b/0x470 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0xe53/0x2a00 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xa8/0x120 fs/namespace.c:3072 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007f945d320188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 0000000020000180 RSI: 00000000200005c0 RDI: 0000000020000500 RBP: 00000000004bfb23 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007ffe50f7158f R14: 00007f945d320300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/1533: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by syz-executor.1/31410: #0: (&bdev->bd_fsfreeze_mutex){+.+.}, at: [] mount_bdev+0x71/0x360 fs/super.c:1101 #1: (&type->s_umount_key#95){+.+.}, at: [] grab_super+0x55/0x140 fs/super.c:373 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.231-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5b9/0xb40 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4620 Comm: systemd-journal Not tainted 4.14.231-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a16a8040 task.stack: ffff8880a16b0000 RIP: 0010:unwind_next_frame+0x7d5/0x17d0 arch/x86/kernel/unwind_orc.c:360 RSP: 0018:ffff8880a16b7a18 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 1ffff110142d6f4a RCX: ffffffff8a7219cc RDX: 1ffff110142d6f63 RSI: 0000000000000001 RDI: ffff8880a16b7b18 RBP: 0000000000000001 R08: ffffffff8a7219d0 R09: ffffffff8a7219d1 R10: 000000000001e862 R11: 0000000000066071 R12: ffff8880a16b7b0d R13: ffff8880a16b7b10 R14: ffff8880a16b7b28 R15: ffff8880a16b7ad8 FS: 00007f38343f08c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f38313a0000 CR3: 00000000a1fee000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __save_stack_trace+0x90/0x160 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 aa_free_task_context+0xda/0x130 security/apparmor/context.c:54 apparmor_cred_free+0x34/0x70 security/apparmor/lsm.c:58 security_cred_free+0x71/0xb0 security/security.c:1003 put_cred_rcu+0xe3/0x300 kernel/cred.c:117 __put_cred+0x1a1/0x210 kernel/cred.c:151 put_cred include/linux/cred.h:271 [inline] SYSC_faccessat fs/open.c:444 [inline] SyS_faccessat+0x52a/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f38336ab9c7 RSP: 002b:00007ffe91777778 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffe9177a7a0 RCX: 00007f38336ab9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055a1ac0739a3 RBP: 00007ffe917778c0 R08: 000055a1ac0693e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 000055a1ad4888a0 R15: 00007ffe91777db0 Code: 40 60 48 89 44 24 58 e9 18 fc ff ff 49 8d 7f 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 40 0f 00 00 <48> 89 c8 49 8b 57 40 48 be 00 00 00 00 00 fc ff df 48 c1 e8 03