INFO: task syz-executor.2:2480 blocked for more than 143 seconds. Not tainted 5.8.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28384 2480 15793 0x00000004 Call Trace: context_switch kernel/sched/core.c:3458 [inline] __schedule+0x8ea/0x2210 kernel/sched/core.c:4219 schedule+0xd0/0x2a0 kernel/sched/core.c:4294 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4353 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103 _vb2_fop_release+0x38/0x280 drivers/media/common/videobuf2/videobuf2-v4l2.c:1047 v4l2_release+0x2e7/0x390 drivers/media/v4l2-core/v4l2-dev.c:455 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:239 [inline] __prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:269 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x415ee1 Code: Bad RIP value. RSP: 002b:00007ffe478b0700 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000415ee1 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000007903d0 R09: 0000000000000000 R10: 00007ffe478b07e0 R11: 0000000000000293 R12: 00000000007903d8 R13: 0000000000000001 R14: ffffffffffffffff R15: 000000000078bfac INFO: task syz-executor.4:2497 blocked for more than 144 seconds. Not tainted 5.8.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28720 2497 7248 0x00004006 Call Trace: context_switch kernel/sched/core.c:3458 [inline] __schedule+0x8ea/0x2210 kernel/sched/core.c:4219 schedule+0xd0/0x2a0 kernel/sched/core.c:4294 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4353 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10d0 kernel/locking/mutex.c:1103 _vb2_fop_release+0x38/0x280 drivers/media/common/videobuf2/videobuf2-v4l2.c:1047 v4l2_release+0x2e7/0x390 drivers/media/v4l2-core/v4l2-dev.c:455 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 get_signal+0xd6c/0x1ee0 kernel/signal.c:2547 do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 exit_to_usermode_loop arch/x86/entry/common.c:235 [inline] __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:269 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c369 Code: Bad RIP value. RSP: 002b:00007f6a10e66c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffe00 RBX: 000000000001dd80 RCX: 000000000045c369 RDX: 00000000200000c0 RSI: 00000000c100565c RDI: 0000000000000003 RBP: 000000000078bf40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c R13: 00007ffc1a83e61f R14: 00007f6a10e679c0 R15: 000000000078bf0c Showing all locks held in the system: 2 locks held by systemd/1: 1 lock held by khungtaskd/1140: #0: ffffffff89bc11c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5779 1 lock held by kswapd0/1673: 2 locks held by systemd-journal/3887: 2 locks held by systemd-udevd/3890: #0: ffff8880a37ac310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 3 locks held by systemd-timesyn/4143: 2 locks held by cron/6527: #0: ffff8880a37ac310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by in:imklog/6537: #0: ffff8880a37ac310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by rs:main Q:Reg/6538: #0: ffff888092143310 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by syz-fuzzer/6846: #0: ffff8880878df810 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by syz-fuzzer/6849: #0: ffff8880878df810 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by syz-fuzzer/2057: #0: ffff8880878df810 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by syz-executor.4/7248: #0: ffff888087a90850 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 2 locks held by kworker/u4:6/8734: #0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1261 [inline] #0: ffff8880ae635e18 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x22f/0x2210 kernel/sched/core.c:4137 #1: ffff8880ae620f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2fb/0x400 kernel/sched/psi.c:817 1 lock held by syz-executor.3/7558: 3 locks held by kworker/u4:8/32037: 1 lock held by syz-executor.2/2480: #0: ffff888217088bd8 (&vcap->lock){+.+.}-{3:3}, at: _vb2_fop_release+0x38/0x280 drivers/media/common/videobuf2/videobuf2-v4l2.c:1047 2 locks held by syz-executor.2/2488: #0: ffff888217088bd8 (&vcap->lock){+.+.}-{3:3}, at: __video_do_ioctl+0x49e/0xc70 drivers/media/v4l2-core/v4l2-ioctl.c:2954 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 1 lock held by syz-executor.4/2497: #0: ffff888217088bd8 (&vcap->lock){+.+.}-{3:3}, at: _vb2_fop_release+0x38/0x280 drivers/media/common/videobuf2/videobuf2-v4l2.c:1047 2 locks held by systemd-udevd/2551: #0: ffff8880a37aa290 (&ei->i_mmap_sem){++++}-{3:3}, at: ext4_filemap_fault+0x7f/0xb6 fs/ext4/inode.c:6059 #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4202 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: fs_reclaim_release mm/page_alloc.c:4198 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4227 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4244 [inline] #1: ffffffff89c6c260 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath.constprop.0+0x1554/0x2780 mm/page_alloc.c:4650 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1140 Comm: khungtaskd Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline] watchdog+0xd7d/0x1000 kernel/hung_task.c:295 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 38 Comm: kworker/u4:2 Not tainted 5.8.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x60 kernel/kcov.c:197 Code: 5d be 03 00 00 00 e9 76 e3 23 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 48 8b 14 25 00 ff 01 00 <65> 8b 05 e0 41 8e 7e a9 00 01 ff 00 48 8b 34 24 74 0f f6 c4 01 74 RSP: 0000:ffffc90000e97c78 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff87caeac9 RDX: ffff8880a91183c0 RSI: ffff8880a91183c0 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8c59aa27 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: dffffc0000000000 R15: 000000000000035a FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000416160 CR3: 000000008dfa3000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_read_unlock include/linux/rcupdate.h:684 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0xa68/0xe50 net/batman-adv/network-coding.c:718 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293