INFO: task syz-executor.4:23629 blocked for more than 140 seconds. Not tainted 4.9.155+ #27 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D26552 23629 3838 0x00000004 ffff8801d3bbdf00 ffff8801a5e9d800 ffff8801db621000 ffff8801a5e797c0 ffff8801db621018 ffff8801a650f450 ffffffff82806806 dffffc0000000000 ffff8801a650f428 ffffffff81207081 00ffffff8281290b ffff8801db6218f0 Call Trace: [] schedule+0x92/0x1c0 kernel/sched/core.c:3553 [] rwsem_down_read_failed+0x258/0x3e0 kernel/locking/rwsem-xadd.c:260 [] call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 [] __down_read arch/x86/include/asm/rwsem.h:65 [inline] [] down_read+0x52/0xb0 kernel/locking/rwsem.c:24 [] inode_lock_shared include/linux/fs.h:778 [inline] [] ext4_direct_IO_read fs/ext4/inode.c:3595 [inline] [] ext4_direct_IO+0x51f/0x29c0 fs/ext4/inode.c:3662 [] generic_file_read_iter+0xaaf/0x1ac0 mm/filemap.c:1964 [] generic_file_splice_read+0x28c/0x4c0 fs/splice.c:309 [] do_splice_to+0x108/0x170 fs/splice.c:899 [] splice_direct_to_actor+0x246/0x820 fs/splice.c:971 [] do_splice_direct+0x1a5/0x260 fs/splice.c:1080 [] do_sendfile+0x503/0xc00 fs/read_write.c:1395 [] SYSC_sendfile64 fs/read_write.c:1456 [inline] [] SyS_sendfile64+0x145/0x160 fs/read_write.c:1442 [] do_syscall_64+0x1ad/0x570 arch/x86/entry/common.c:285 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Showing all locks held in the system: 2 locks held by khungtaskd/24: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x11b/0xa40 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/1909: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0xa8/0xd0 fs/file.c:781 2 locks held by getty/2037: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.4/23629: #0: (sb_writers#4){.+.+.+}, at: [] file_start_write include/linux/fs.h:2642 [inline] #0: (sb_writers#4){.+.+.+}, at: [] do_sendfile+0x93a/0xc00 fs/read_write.c:1394 #1: (&sb->s_type->i_mutex_key#9){++++++}, at: [] inode_lock_shared include/linux/fs.h:778 [inline] #1: (&sb->s_type->i_mutex_key#9){++++++}, at: [] ext4_direct_IO_read fs/ext4/inode.c:3595 [inline] #1: (&sb->s_type->i_mutex_key#9){++++++}, at: [] ext4_direct_IO+0x51f/0x29c0 fs/ext4/inode.c:3662 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.155+ #27 ffff8801d9907cd0 ffffffff81b47871 0000000000000000 0000000000000000 0000000000000000 ffffffff81097301 00000000003ffd5d ffff8801d9907d08 ffffffff81b52afc 0000000000000000 0000000000000000 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x120 lib/dump_stack.c:51 [] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x5f7/0xa40 kernel/hung_task.c:239 [] kthread+0x278/0x310 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13336 Comm: syz-executor.1 Not tainted 4.9.155+ #27 task: ffff8801a5e797c0 task.stack: ffff8801ab898000 RIP: 0033:[<000000000040159b>] c [<000000000040159b>] 0x40159b RSP: 002b:00007f2ee5672690 EFLAGS: 00000286 RAX: 00000000baeaab3a RBX: 000000000000000b RCX: 0000000000458079 RDX: 0000000100000000 RSI: 00007f2ee56726c0 RDI: 000000000000000b RBP: 0000000000000000 R08: 0077697275636573 R09: 0000000000000000 R10: 25328dfb00000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f2ee5673700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42b50c000 CR3: 00000001a673e000 CR4: 00000000001606b0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600