INFO: task syz-executor.2:18176 can't die for more than 143 seconds. task:syz-executor.2 state:D stack:27224 pid:18176 ppid: 8497 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 inode_lock include/linux/fs.h:773 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2214 do_new_mount_fc fs/namespace.c:2842 [inline] do_new_mount fs/namespace.c:2901 [inline] path_mount+0x1678/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e299 RSP: 002b:00007fa771521c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e299 RDX: 0000000020002100 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffd8afd946f R14: 00007fa7715229c0 R15: 000000000119c034 INFO: task syz-executor.2:18176 blocked for more than 143 seconds. Not tainted 5.10.0-next-20201223-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:27224 pid:18176 ppid: 8497 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 inode_lock include/linux/fs.h:773 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2214 do_new_mount_fc fs/namespace.c:2842 [inline] do_new_mount fs/namespace.c:2901 [inline] path_mount+0x1678/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e299 RSP: 002b:00007fa771521c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e299 RDX: 0000000020002100 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119c078 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007ffd8afd946f R14: 00007fa7715229c0 R15: 000000000119c034 INFO: task syz-executor.2:18178 can't die for more than 144 seconds. task:syz-executor.2 state:R running task stack:27088 pid:18178 ppid: 8497 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8cd/0x2150 kernel/sched/core.c:5078 Showing all locks held in the system: 1 lock held by khungtaskd/1656: #0: ffffffff8b363660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8183: #0: ffff88801436ed70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:949 3 locks held by rs:main Q:Reg/8184: 2 locks held by agetty/8195: #0: ffff8880214e6098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:266 #1: ffffc900011cc2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x21d/0x1aa0 drivers/tty/n_tty.c:2158 1 lock held by syz-executor.2/18176: #0: ffff888074c70150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff888074c70150 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2214 2 locks held by syz-executor.2/18178: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1656 Comm: khungtaskd Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 25 Comm: kworker/u4:1 Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: phy11 ieee80211_iface_work RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0xc/0x12 Code: 56 57 41 50 41 51 41 52 41 53 e8 8f 15 00 00 41 5b 41 5a 41 59 41 58 5f 5e 5a 59 c3 66 90 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <3c> 01 75 02 5a c3 56 0f b6 f0 e8 c5 ff ff ff 5e 5a c3 66 90 48 b8 RSP: 0018:ffffc90000dff5b0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffff8880203dc468 RCX: ffffffff81594270 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888074848158 RBP: ffff888074848158 R08: 0000000000000000 R09: ffff88807484815b R10: ffffed100e90902b R11: 0000000000000000 R12: ffff888074848160 R13: ffff888074848168 R14: 0005b7b7c657e5af R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa482bae000 CR3: 00000000259ba000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:559 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:56 [inline] do_raw_spin_unlock+0x171/0x230 kernel/locking/spinlock_debug.c:139 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:175 [inline] _raw_spin_unlock_bh+0x1a/0x30 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:399 [inline] cfg80211_put_bss+0x1b0/0x270 net/wireless/scan.c:2499 ieee80211_rx_bss_put net/mac80211/scan.c:37 [inline] ieee80211_rx_bss_put+0x3f/0x50 net/mac80211/scan.c:32 ieee80211_rx_bss_info net/mac80211/ibss.c:1198 [inline] ieee80211_rx_mgmt_probe_beacon+0xdde/0x16b0 net/mac80211/ibss.c:1615 ieee80211_ibss_rx_queued_mgmt+0xe3e/0x1870 net/mac80211/ibss.c:1642 ieee80211_iface_work+0x761/0x9e0 net/mac80211/iface.c:1423 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296