INFO: task syz.3.22:6635 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.22 state:D stack:28024 pid:6635 tgid:6630 ppid:6303 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x16d9/0x5700 kernel/sched/core.c:7270
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x16d9/0x5700 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7643
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f88/0x25b0 kernel/locking/rtmutex.c:1787
rt_mutex_slowlock+0xbd/0x180 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251
inode_lock include/linux/fs.h:1024 [inline]
generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61e/0xbb0 fs/read_write.c:687
ksys_write+0x156/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f553275c819
RSP: 002b:00007f5531d9d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f55329d6090 RCX: 00007f553275c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f55327f2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f55329d6128 R14: 00007f55329d6090 R15: 00007ffc6982f7c8
INFO: task syz.1.18:6772 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.18 state:D stack:28904 pid:6772 tgid:6764 ppid:6298 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x16d9/0x5700 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7643
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f88/0x25b0 kernel/locking/rtmutex.c:1787
rt_mutex_slowlock+0xbd/0x180 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251
inode_lock include/linux/fs.h:1024 [inline]
generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x61e/0xbb0 fs/read_write.c:687
ksys_write+0x156/0x270 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f61dca1c819
RSP: 002b:00007f61dc05d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f61dcc96090 RCX: 00007f61dca1c819
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f61dcab2c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f61dcc96128 R14: 00007f61dcc96090 R15: 00007ffcbb488da8
Showing all locks held in the system:
locks held by pr/ttyS0/17: 3, last CPU#0:
#0: ffffffff8e09d578 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
#0: ffffffff8e09d578 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:439 [inline]
#0: ffffffff8e09d578 (console_srcu){....}-{0:0}, at: console_srcu_read_lock+0x30/0x60 kernel/printk/printk.c:291
#1: ffffffff99e991f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_emit_one kernel/printk/nbcon.c:1137 [inline]
#1: ffffffff99e991f8 (&port_lock_key){+.+.}-{3:3}, at: nbcon_kthread_func+0x64c/0x880 kernel/printk/nbcon.c:1271
#2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57
locks held by khungtaskd/38: 1, last CPU#1:
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by kworker/u8:31/3288: 5, last CPU#0:
#0: ffff888033926938 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff888033926938 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff888033926938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff888033926938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000f52fc40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000f52fc40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000f52fc40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000f52fc40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffffffff8e0594c0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3d/0x420 kernel/softirq.c:186
#3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3d/0x420 kernel/softirq.c:186
#4: ffff8880452c6d58 (&hash->list_locks[i]){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
#4: ffff8880452c6d58 (&hash->list_locks[i]){+...}-{3:3}, at: __batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:240
locks held by getty/5357: 2, on CPU#0:
#0: ffff888036e8b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900044cb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u9:4/6312: 3, on CPU#1:
#0: ffff8880395b2138 ((wq_completion)hci9){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff8880395b2138 ((wq_completion)hci9){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff8880395b2138 ((wq_completion)hci9){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff8880395b2138 ((wq_completion)hci9){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc90004697c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc90004697c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc90004697c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc90004697c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff8880601d8f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331
locks held by syz.3.22/6632: 3, on CPU#1:
#0: ffff88803e1f6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88803e1f6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff888045b728b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff888045b728b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.3.22/6635: 3, on CPU#1:
#0: ffff88803ce3e928 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88803e1f6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88803e1f6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff888045b728b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff888045b728b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.1.18/6766: 3, on CPU#1:
#0: ffff88801153a510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88801153a510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805d5128b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805d5128b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.1.18/6772: 3, on CPU#0:
#0: ffff888031e0df28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88801153a510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88801153a510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805d5128b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805d5128b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.0.17/6785: 3, on CPU#0:
#0: ffff88802b3b2510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88802b3b2510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805d510af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805d510af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.0.17/6790: 3, on CPU#1:
#0: ffff8880342e5f28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88802b3b2510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88802b3b2510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805d510af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805d510af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.4.21/6802: 3, last CPU#1:
#0: ffff888011940510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff888011940510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805c406430 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805c406430 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.4.21/6809: 3, on CPU#0:
#0: ffff8880364a0d28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff888011940510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff888011940510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805c406430 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805c406430 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.2.24/6807: 3, on CPU#1:
#0: ffff88803ec4c510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88803ec4c510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff888045b70380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff888045b70380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.2.24/6808: 3, on CPU#1:
#0: ffff8880364a1528 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88803ec4c510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88803ec4c510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff888045b70380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff888045b70380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.5.25/6851: 3, on CPU#1:
#0: ffff88803bbc6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88803bbc6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805d515cc0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805d515cc0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.5.25/6852: 3, on CPU#0:
#0: ffff888039c12128 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88803bbc6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88803bbc6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805d515cc0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805d515cc0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.6.26/7010: 3, on CPU#1:
#0: ffff88805ff50510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88805ff50510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805c404670 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805c404670 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.6.26/7014: 3, on CPU#1:
#0: ffff88803a0ee328 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88805ff50510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88805ff50510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805c404670 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805c404670 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.7.27/7042: 3, on CPU#1:
#0: ffff8880299fa510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff8880299fa510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805c4028b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805c4028b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.7.27/7043: 3, on CPU#0:
#0: ffff88803964e128 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff8880299fa510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff8880299fa510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805c4028b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805c4028b0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.8.28/7045: 3, on CPU#1:
#0: ffff8880333e6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff8880333e6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff888062558380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff888062558380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.8.28/7046: 3, on CPU#0:
#0: ffff888033b62328 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff8880333e6510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff8880333e6510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff888062558380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff888062558380 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz.9.29/7048: 3, on CPU#1:
#0: ffff88803c206510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#0: ffff88803c206510 (sb_writers#12){.+.+}-{0:0}, at: vfs_writev+0x2b5/0x990 fs/read_write.c:1056
#1: ffff88805d515550 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#1: ffff88805d515550 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffffffff8e419e38 (fat12_entry_lock){+.+.}-{3:3}, at: fat12_ent_get+0x28/0x200 fs/fat/fatent.c:125
locks held by syz.9.29/7055: 3, on CPU#0:
#0: ffff888034a47128 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88803c206510 (sb_writers#12){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
#1: ffff88803c206510 (sb_writers#12){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffff88805d515550 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#2: ffff88805d515550 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
locks held by syz-executor/7390: 1, last CPU#1:
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz-executor/7429: 10, last CPU#0:
#0: ffffffff8e29eaf0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
#0: ffffffff8e29eaf0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x10f/0x480 kernel/fork.c:1595
#1: ffff888065059f30 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
#1: ffff888065059f30 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x18e/0x1d80 mm/mmap.c:1716
#2: ffff888066f83a30 (&mm->mmap_lock/1){+.+.}-{4:4}, at: mmap_write_lock_nested include/linux/mmap_lock.h:552 [inline]
#2: ffff888066f83a30 (&mm->mmap_lock/1){+.+.}-{4:4}, at: dup_mmap+0x27d/0x1d80 mm/mmap.c:1723
#3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
#4: ffff88806887f718 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#4: ffff88806887f718 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
#5: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#5: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#5: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#5: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57
#6: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#6: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#6: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
#7: ffff8880384584d8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pte_range mm/memory.c:1354 [inline]
#7: ffff8880384584d8 (ptlock_ptr(ptdesc)#2/1){+.+.}-{3:3}, at: copy_pmd_range+0x569/0x58f0 mm/memory.c:1490
#8: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#8: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#8: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#8: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock_nested+0x1e0/0x400 kernel/locking/spinlock_rt.c:65
#9: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#9: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#9: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: page_table_check_set+0x127/0x530 mm/page_table_check.c:112
locks held by syz-executor/7452: 2, last CPU#1:
#0: ffff88805d4c38b8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff88805d4c38b8 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:734
#1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
#1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by kworker/u9:5/9249: 3, on CPU#0:
#0: ffff88805dedd938 ((wq_completion)hci8){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffff88805dedd938 ((wq_completion)hci8){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffff88805dedd938 ((wq_completion)hci8){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#0: ffff88805dedd938 ((wq_completion)hci8){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#1: ffffc9000765fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffc9000765fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffc9000765fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
#1: ffffc9000765fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
#2: ffff888045f00f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331
locks held by dhcpcd/12058: 1, on CPU#1:
#0: ffff88805d4c1038 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff88805d4c1038 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:734
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/ttyS0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 be aa 65 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 af 67 d1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001678b8 EFLAGS: 00000202
RAX: 1ffffffff33d3200 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff8560ceb0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99e99220 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125bd4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdd1be17dac CR3: 000000002cbc2000 CR4: 00000000003526f0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x190/0x300 drivers/tty/serial/8250/8250_port.c:2013
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
__serial8250_console_fifo_write+0xd0/0x3f0 drivers/tty/serial/8250/8250_port.c:3345
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
__serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
serial8250_console_write+0xac5/0x1230 drivers/tty/serial/8250/8250_port.c:3493
nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
kthread+0x38b/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245