do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000160020b1>] n_hdlc_tty_read+0x32a/0x810 drivers/tty/n_hdlc.c:589 WARNING: CPU: 0 PID: 15387 at kernel/sched/core.c:6094 __might_sleep+0x13d/0x190 kernel/sched/core.c:6094 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 15387 Comm: syz-executor3 Not tainted 5.0.0-rc2+ #32 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+0x1db/0x2d0 lib/dump_stack.c:113 audit: type=1804 audit(1547870000.436:2795): pid=15363 uid=0 auid=4294967295 ses=4294967295 subj=_ op=invalid_pcr cause=ToMToU comm="syz-executor1" name="/root/syzkaller-testdir411331326/syzkaller.PmyciT/2479/memory.events" dev="sda1" ino=17699 res=1 panic+0x2cb/0x65c kernel/panic.c:214 __warn.cold+0x20/0x48 kernel/panic.c:571 report_bug+0x263/0x2b0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] fixup_bug arch/x86/kernel/traps.c:173 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 RIP: 0010:__might_sleep+0x13d/0x190 kernel/sched/core.c:6094 Code: 65 48 8b 1c 25 40 ee 01 00 48 8d 7b 10 48 89 fe 48 c1 ee 03 80 3c 06 00 75 2b 48 8b 73 10 48 c7 c7 c0 23 4b 88 e8 c3 13 f3 ff <0f> 0b e9 43 ff ff ff e8 f7 b5 6d 00 e9 26 ff ff ff e8 ed b5 6d 00 RSP: 0018:ffff88805d0d79a8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888084936700 RCX: ffffc9000c7d8000 RDX: 0000000000014a16 RSI: ffffffff81685456 RDI: 0000000000000005 RBP: ffff88805d0d79d8 R08: ffff888084936700 R09: ffffed1015cc5021 R10: ffffed1015cc5020 R11: ffff8880ae628107 R12: ffffffff88819660 audit: type=1804 audit(1547870000.436:2796): pid=15369 uid=0 auid=4294967295 ses=4294967295 subj=_ op=invalid_pcr cause=open_writers comm="syz-executor1" name="/root/syzkaller-testdir411331326/syzkaller.PmyciT/2479/memory.events" dev="sda1" ino=17699 res=1 R13: 0000000000000019 R14: 0000000000000000 R15: ffff888084936700 __might_fault+0xc6/0x1e0 mm/memory.c:4379 _copy_to_user+0x30/0x120 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:152 [inline] n_hdlc_tty_read+0x60f/0x810 drivers/tty/n_hdlc.c:600 tty_read+0x196/0x2a0 drivers/tty/tty_io.c:866 __vfs_read+0x116/0xb20 fs/read_write.c:416 vfs_read+0x194/0x3e0 fs/read_write.c:452 ksys_read+0x105/0x260 fs/read_write.c:578 __do_sys_read fs/read_write.c:588 [inline] __se_sys_read fs/read_write.c:586 [inline] __x64_sys_read+0x73/0xb0 fs/read_write.c:586 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458099 Code: 6d 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fbe2bcb1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099 RDX: 0000000000001000 RSI: 0000000020000180 RDI: 0000000000000003 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbe2bcb26d4 R13: 00000000004c4c0a R14: 00000000004d83c8 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds..