INFO: task syz.4.199:5585 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.199 state:D stack:0 pid:5585 tgid:5584 ppid:4671 task_flags:0x400140 flags:0x00000011 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1b74/0x2d24 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xa4/0x140 kernel/sched/core.c:7282 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7339 __mutex_lock_common+0x98c/0x20f4 kernel/locking/mutex.c:726 __mutex_lock kernel/locking/mutex.c:820 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:873 sync_bdevs+0x210/0x3dc block/bdev.c:1296 ksys_sync+0xc4/0x118 fs/sync.c:105 __arm64_sys_sync+0x14/0x24 fs/sync.c:111 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x25c arch/arm64/kernel/entry-common.c:723 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 INFO: task syz.4.199:5592 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.199 state:D stack:0 pid:5592 tgid:5584 ppid:4671 task_flags:0x400040 flags:0x00800011 Call trace: __switch_to+0x2b0/0x6e0 arch/arm64/kernel/process.c:810 (T) context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1b74/0x2d24 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xa4/0x140 kernel/sched/core.c:7282 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:7339 __mutex_lock_common+0x98c/0x20f4 kernel/locking/mutex.c:726 __mutex_lock kernel/locking/mutex.c:820 [inline] mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:873 sync_bdevs+0x210/0x3dc block/bdev.c:1296 ksys_sync+0xc4/0x118 fs/sync.c:105 __arm64_sys_sync+0x14/0x24 fs/sync.c:111 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x25c arch/arm64/kernel/entry-common.c:723 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:742 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff0000c002b540 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x640/0x173c kernel/workqueue.c:3276 #1: ffff80008e9e7be0 (rx_mode_work){+.+.}-{0:0}, at: process_one_work+0x6a4/0x173c kernel/workqueue.c:3276 #2: ffff800089b85900 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80 1 lock held by khungtaskd/31: #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: __ll_sc_atomic64_fetch_or arch/arm64/include/asm/atomic_ll_sc.h:-1 [inline] #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: arch_atomic64_fetch_or arch/arm64/include/asm/atomic.h:86 [inline] #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: raw_atomic64_fetch_or include/linux/atomic/atomic-arch-fallback.h:3816 [inline] #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: raw_atomic_long_fetch_or include/linux/atomic/atomic-long.h:1090 [inline] #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: arch_test_and_set_bit include/asm-generic/bitops/atomic.h:42 [inline] #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:72 [inline] #0: ffff800088ac66e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x0/0x44 kernel/sched/sched.h:3869 3 locks held by kworker/u8:5/1161: #0: ffff0000ceb96940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x640/0x173c kernel/workqueue.c:3276 #1: ffff800094697be0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6a4/0x173c kernel/workqueue.c:3276 #2: ffff800089b85900 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80 2 locks held by syslogd/4287: 1 lock held by udevd/4302: 2 locks held by getty/4451: #0: ffff0000d3a190a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340 #1: ffff80009228b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x354/0xf84 drivers/tty/n_tty.c:2211 1 lock held by udevd/4662: #0: ffff0000c7aa4350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xcc/0x8cc block/bdev.c:953 1 lock held by udevd/5024: #0: ffff0000c7f56350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xcc/0x8cc block/bdev.c:953 1 lock held by syz.4.199/5585: #0: ffff0000c7aa4350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x210/0x3dc block/bdev.c:1296 1 lock held by syz.4.199/5592: #0: ffff0000c7aa4350 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x210/0x3dc block/bdev.c:1296 3 locks held by syz-executor/5857: 3 locks held by syz-executor/6695: 3 locks held by syz.0.1086/9776: #0: ffff8000892ba048 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire+0x18/0x54 include/linux/srcu.h:186 #1: ffff800089b85900 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffff800089b85900 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock+0x38/0x10c net/core/rtnetlink.c:341 #2: ffff800088acbce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #2: ffff800088acbce8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x34c/0x67c kernel/rcu/tree_exp.h:961 1 lock held by syz.9.1087/9780: #0: ffff0000cd185eb0 (&dev->mutex#4){+.+.}-{4:4}, at: vb2_fop_read+0xf0/0x2f0 drivers/media/common/videobuf2/videobuf2-v4l2.c:1210 =============================================