INFO: task syz-executor.1:19233 can't die for more than 143 seconds. syz-executor.1 R running task 27112 19233 31562 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:ffff888093b0fb68 EFLAGS: 00010206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: ffff88808c2cc640 RCX: 0000000000000400 RDX: 0000000000001000 RSI: ffffc9000ee0f400 RDI: ffff88808c2cca40 RBP: ffff888093b0fb98 R08: ffff88805c80a280 R09: ffff8880aa402000 R10: 0000000000000000 R11: ffffea000230b307 R12: 0000000000001000 R13: 00007ffffffff000 R14: ffffc9000ee0f000 R15: ffff88805c80a280 read_mem+0xfc/0x2c0 drivers/char/mem.c:163 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x4a4/0x660 fs/read_write.c:935 vfs_readv+0xf0/0x160 fs/read_write.c:997 do_preadv+0x1c4/0x280 fs/read_write.c:1089 __do_sys_preadv fs/read_write.c:1139 [inline] __se_sys_preadv fs/read_write.c:1134 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1134 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: Bad RIP value. RSP: 002b:00007f7c1e7e1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459829 RDX: 0000000000000002 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000bffff000 R11: 0000000000000246 R12: 00007f7c1e7e26d4 R13: 00000000004c6b38 R14: 00000000004dbc88 R15: 00000000ffffffff INFO: task syz-executor.1:19272 can't die for more than 143 seconds. syz-executor.1 R running task 28400 19272 31562 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 INFO: task syz-executor.4:19293 can't die for more than 144 seconds. syz-executor.4 R running task 27752 19293 19275 0x80004006 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17d0 kernel/sched/core.c:3937 INFO: task syz-executor.4:19297 can't die for more than 144 seconds. syz-executor.4 R running task 28400 19297 19275 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 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 PID: 1059 Comm: khungtaskd Not tainted 5.3.0-rc3-next-20190809 #63 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: 19297 Comm: syz-executor.4 Not tainted 5.3.0-rc3-next-20190809 #63 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:ffff88809888fb68 EFLAGS: 00010206 RAX: 0000000000040000 RBX: ffff88806c92ea80 RCX: 0000000000000000 RDX: 0000000000001000 RSI: ffffc9000eea6000 RDI: ffff88806c92fa80 RBP: ffff88809888fb98 R08: ffff88806ac20540 R09: ffff8880aa402000 R10: 0000000000000000 R11: ffffea0001b24b87 R12: 0000000000001000 R13: 00007ffffffff000 R14: ffffc9000eea5000 R15: ffff88806ac20540 FS: 00007fdfe9d53700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 000000008fe8b000 CR4: 00000000001426f0 Call Trace: read_mem+0xfc/0x2c0 drivers/char/mem.c:163 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x4a4/0x660 fs/read_write.c:935 vfs_readv+0xf0/0x160 fs/read_write.c:997 do_preadv+0x1c4/0x280 fs/read_write.c:1089 __do_sys_preadv fs/read_write.c:1139 [inline] __se_sys_preadv fs/read_write.c:1134 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1134 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 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:00007fdfe9d52c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000459829 RDX: 0000000000000002 RSI: 0000000020000200 RDI: 0000000000000004 RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000c0000000 R11: 0000000000000246 R12: 00007fdfe9d536d4 R13: 00000000004c6b38 R14: 00000000004dbc88 R15: 00000000ffffffff