INFO: task syz-executor.1:20641 can't die for more than 143 seconds. syz-executor.1 R running task 27776 20641 9054 0x80004006 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17d0 kernel/sched/core.c:3937 preempt_schedule_irq+0xb5/0x160 kernel/sched/core.c:4185 retint_kernel+0x1b/0x2b RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:205 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4 RSP: 0018:ffff88805890faf8 EFLAGS: 00010206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffff888059b3ce40 RCX: 0000000000000c00 RDX: 0000000000001000 RSI: ffffc90015494400 RDI: ffff888059b3d240 RBP: ffffffff81724d38 R08: ffffffff81724cb8 R09: ffffffff8133b140 R10: 0000000000000000 R11: ffffea000166cf07 R12: 0000000000001000 R13: 00007ffffffff000 R14: ffffc9001549a000 R15: ffff888049b4e4c0 read_mem+0x11e/0x500 drivers/char/mem.c:166 do_loop_readv_writev.part.0+0xe2/0x460 fs/read_write.c:717 do_loop_readv_writev fs/read_write.c:706 [inline] do_iter_read+0x300/0x390 fs/read_write.c:941 vfs_readv+0xf0/0x160 fs/read_write.c:1003 do_preadv+0x1c4/0x280 fs/read_write.c:1095 __do_sys_preadv fs/read_write.c:1145 [inline] __se_sys_preadv fs/read_write.c:1140 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1140 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459879 Code: Bad RIP value. RSP: 002b:00007f3527f8bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459879 RDX: 0000000000000001 RSI: 0000000020000200 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000febfffff R11: 0000000000000246 R12: 00007f3527f8c6d4 R13: 00000000004c6b98 R14: 00000000004dbd88 R15: 00000000ffffffff INFO: task syz-executor.1:21133 can't die for more than 144 seconds. syz-executor.1 R running task 28016 21133 9054 0x80004006 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17d0 kernel/sched/core.c:3937 Showing all locks held in the system: 1 lock held by khungtaskd/1064: #0: ffffffff88fa9440 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5337 2 locks held by udevd/3891: 1 lock held by rsyslogd/8921: #0: ffff88808da21660 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/9011: #0: ffff88808d81cc10 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f2d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9012: #0: ffff8880909c6210 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9013: #0: ffff8880976d0210 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9014: #0: ffff8880a4574bd0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9015: #0: ffff8880a22eaa10 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9016: #0: ffff8880a4574350 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 2 locks held by getty/9017: #0: ffff8880995360d0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1c10 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1064 Comm: khungtaskd Not tainted 5.3.0-rc5-next-20190823 #72 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:269 [inline] watchdog+0xc99/0x1360 kernel/hung_task.c:353 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 20641 Comm: syz-executor.1 Not tainted 5.3.0-rc5-next-20190823 #72 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:205 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 1f 00 c3 0f 1f 80 00 00 00 00 0f 1f 00 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 1f 00 c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4 RSP: 0018:ffff88805890faf8 EFLAGS: 00010206 RAX: 0000000000040000 RBX: ffff888059b3ce40 RCX: 0000000000000400 RDX: 0000000000001000 RSI: ffffc900154cec00 RDI: ffff888059b3da40 RBP: ffff88805890fb28 R08: ffff888049b4e4c0 R09: ffff8880aa402000 R10: 0000000000000000 R11: ffffea000166cf07 R12: 0000000000001000 R13: 00007ffffffff000 R14: ffffc900154ce000 R15: ffff888049b4e4c0 FS: 00007f3527f8c700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000009f990000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: read_mem+0x11e/0x500 drivers/char/mem.c:166 do_loop_readv_writev.part.0+0xe2/0x460 fs/read_write.c:717 do_loop_readv_writev fs/read_write.c:706 [inline] do_iter_read+0x300/0x390 fs/read_write.c:941 vfs_readv+0xf0/0x160 fs/read_write.c:1003 do_preadv+0x1c4/0x280 fs/read_write.c:1095 __do_sys_preadv fs/read_write.c:1145 [inline] __se_sys_preadv fs/read_write.c:1140 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1140 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459879 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3527f8bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459879 RDX: 0000000000000001 RSI: 0000000020000200 RDI: 0000000000000005 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000febfffff R11: 0000000000000246 R12: 00007f3527f8c6d4 R13: 00000000004c6b98 R14: 00000000004dbd88 R15: 00000000ffffffff