WARNING in __might

WARNING in __might_sleep (2)
Status: fixed on 2019/03/06 07:43
Reported-by: syzbot+c244af085a0159d22879@syzkaller.appspotmail.com
Fix commit: fc01d8c6 tty/n_hdlc: fix __might_sleep warning
First crash: 865d, last: 834d

similar bugs (3):
Kernel	Title	Repro	Count	Last	Reported	Patched	Status
upstream	WARNING in __might_sleep (3)		6	735d	744d	0/22	closed as invalid on 2019/05/08 12:35
android-49	WARNING in __might_sleep	syz	11	866d	755d	0/3	public: reported syz repro on 2019/04/14 09:28
upstream	WARNING in __might_sleep		6	1108d	1111d	6/22	fixed on 2018/05/08 18:30

Sample crash report:

------------[ cut here ]------------
do not call blocking ops when !TASK_RUNNING; state=1 set at [<00000000b77d0bb9>] n_hdlc_tty_read+0x301/0x7f0 drivers/tty/n_hdlc.c:589
WARNING: CPU: 0 PID: 7931 at kernel/sched/core.c:6099 __might_sleep+0x13d/0x190 kernel/sched/core.c:6094
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7931 Comm: syz-executor965 Not tainted 4.20.0+ #388
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+0x1d3/0x2c6 lib/dump_stack.c:113
 panic+0x2ad/0x55c kernel/panic.c:188
 __warn.cold.8+0x20/0x45 kernel/panic.c:540
 report_bug+0x254/0x2d0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271
 do_invalid_op+0x36/0x40 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 40 e0 2a 88 e8 43 27 f3 ff <0f> 0b e9 43 ff ff ff e8 f7 7e 6c 00 e9 26 ff ff ff e8 ed 7e 6c 00
RSP: 0018:ffff8881d9337948 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8881b8632240 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8164e075 RDI: 0000000000000005
RBP: ffff8881d9337978 R08: ffff8881b8632240 R09: 0000000000000007
R10: 0000000000000000 R11: ffff8881b8632240 R12: ffffffff8860b220
R13: 0000000000000019 R14: 0000000000000000 R15: ffff8881b8632240
 __might_fault+0xc6/0x1e0 mm/memory.c:4357
 _copy_to_user+0x30/0x110 lib/usercopy.c:25
 copy_to_user include/linux/uaccess.h:155 [inline]
 n_hdlc_tty_read+0x5c1/0x7f0 drivers/tty/n_hdlc.c:600
 tty_read+0x194/0x2a0 drivers/tty/tty_io.c:866
 __vfs_read+0x117/0x9b0 fs/read_write.c:416
 vfs_read+0x17f/0x3c0 fs/read_write.c:452
 ksys_read+0x101/0x260 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+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440099
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffd58610488 EFLAGS: 00000207 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440099
RDX: 0000000000000057 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000207 R12: 0000000000401920
R13: 00000000004019b0 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (36):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci-upstream-kasan-gce-root	2018/12/26 09:17	upstream	d8924c0d	8a41a0ad	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2018/12/25 07:26	upstream	8fe28cb5	8a41a0ad	.config	log	report	syz	C
ci-upstream-kasan-gce-smack-root	2018/12/25 02:39	upstream	8fe28cb5	8a41a0ad	.config	log	report	syz	C
ci-upstream-kasan-gce	2018/12/25 01:10	upstream	8fe28cb5	8a41a0ad	.config	log	report	syz	C
ci-upstream-kasan-gce-386	2018/12/25 04:19	upstream	8fe28cb5	8a41a0ad	.config	log	report	syz	C
ci-upstream-linux-next-kasan-gce-root	2018/12/28 05:15	linux-next	6a1d2932	af317504	.config	log	report	syz	C
ci-upstream-kasan-gce-selinux-root	2019/01/25 08:33	upstream	c04e2a78	bfab9cd8	.config	log	report
ci-upstream-kasan-gce	2019/01/25 08:17	upstream	c04e2a78	bfab9cd8	.config	log	report
ci-upstream-kasan-gce	2019/01/24 08:03	upstream	30bac164	56558f63	.config	log	report
ci-upstream-kasan-gce-selinux-root	2019/01/23 19:10	upstream	333478a7	7cf3249c	.config	log	report
ci-upstream-kasan-gce-selinux-root	2019/01/23 19:10	upstream	333478a7	7cf3249c	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/23 19:10	upstream	333478a7	7cf3249c	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/22 14:04	upstream	48b16198	985f75cc	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/21 14:31	upstream	49a57857	badbbeee	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/19 03:53	upstream	d7393226	2103a236	.config	log	report
ci-upstream-kasan-gce-selinux-root	2019/01/19 03:51	upstream	d7393226	2103a236	.config	log	report
ci-upstream-kasan-gce-selinux-root	2019/01/19 03:35	upstream	d7393226	2103a236	.config	log	report
ci-upstream-kasan-gce	2019/01/19 03:30	upstream	d7393226	2103a236	.config	log	report
ci-upstream-kasan-gce-root	2019/01/10 21:41	upstream	ba422731	db9b6579	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/08 04:35	upstream	3bd6e94b	69d69aa9	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/08 02:57	upstream	3bd6e94b	69d69aa9	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/07 15:19	upstream	3bd6e94b	69d69aa9	.config	log	report
ci-upstream-kasan-gce	2019/01/06 05:32	upstream	f1c2f885	53be0a37	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/05 16:03	upstream	3fed6ae4	53be0a37	.config	log	report
ci-upstream-kasan-gce-smack-root	2019/01/05 15:33	upstream	3fed6ae4	53be0a37	.config	log	report
ci-upstream-kasan-gce-selinux-root	2019/01/04 18:09	upstream	96d4f267	0127e3ba	.config	log	report
ci-upstream-kasan-gce	2019/01/02 03:03	upstream	28e8c4bc	3d85f48c	.config	log	report
ci-upstream-kasan-gce	2018/12/30 17:06	upstream	19530313	9942de5f	.config	log	report
ci-upstream-kasan-gce-smack-root	2018/12/29 08:09	upstream	f346b0be	e33ad0f1	.config	log	report
ci-upstream-kasan-gce-smack-root	2018/12/28 17:21	upstream	00c569b5	fc6ae81a	.config	log	report
ci-upstream-kasan-gce	2018/12/25 21:42	upstream	8fe28cb5	8a41a0ad	.config	log	report
ci-upstream-kasan-gce	2018/12/24 23:31	upstream	8fe28cb5	8a41a0ad	.config	log	report
ci-upstream-kasan-gce-386	2019/01/16 12:18	upstream	7939f8be	b47fa78d	.config	log	report
ci-upstream-kasan-gce-386	2019/01/08 03:47	upstream	3bd6e94b	69d69aa9	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/01/18 13:51	linux-next	9673b4aa	5bf17c30	.config	log	report
ci-upstream-linux-next-kasan-gce-root	2019/01/15 06:59	linux-next	5aa6589e	ebacf5cb	.config	log	report