BUG: unable to handle kernel paging request in insert

BUG: unable to handle kernel paging request in insert_char
Status: fixed on 2020/08/14 11:39
Reported-by: syzbot+cc08863f947091905ff4@syzkaller.appspotmail.com
Fix commit: 74752b81 vt: Reject zero-sized screen buffer size.
First crash: 517d, last: 297d

Fix bisection: fixed by (bisect log) :
commit 74752b81eae8ae64e97de222320026367e92c4b5
Author: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Sun Jul 12 11:10:12 2020 +0000

vt: Reject zero-sized screen buffer size.

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	BUG: unable to handle kernel paging request in insert_char	C	inconclusive	done	173	315d	513d	0/22	closed as dup on 2020/07/27 22:45
linux-4.14	BUG: unable to handle kernel paging request in insert_char	C		inconclusive	21	283d	511d	0/1	upstream: reported C repro on 2019/12/13 18:49

Sample crash report:

audit: type=1400 audit(1576533356.474:36): avc:  denied  { map } for  pid=7714 comm="syz-executor137" path="/root/syz-executor137679926" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
BUG: unable to handle kernel paging request at 000000010000000e
PGD 93db6067 P4D 93db6067 PUD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 7714 Comm: syz-executor137 Not tainted 4.19.89-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:memset16 arch/x86/include/asm/string_64.h:43 [inline]
RIP: 0010:scr_memsetw include/linux/vt_buffer.h:36 [inline]
RIP: 0010:insert_char+0x23d/0x450 drivers/tty/vt/vt.c:840
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 01 0f 8e 32 01 00 00 d1 eb 41 0f b7 85 c8 03 00 00 4c 89 ff 89 d9 <f3> 66 ab 49 8d bd 78 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89
RSP: 0018:ffff888092647728 EFLAGS: 00010202
RAX: 0000000000000720 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 1ffff11012078591 RSI: 000000010000000e RDI: 000000010000000e
RBP: ffff888092647770 R08: ffff88807fda4700 R09: 0000000000000005
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: 0000000000000000
R13: ffff8880903c28c0 R14: ffff8880903c2bf4 R15: 000000010000000e
FS:  0000000002652880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000010000000e CR3: 000000009177e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 csi_at drivers/tty/vt/vt.c:1965 [inline]
 do_con_trol+0x3ca8/0x6070 drivers/tty/vt/vt.c:2412
 do_con_write.part.0+0xfd5/0x1eb0 drivers/tty/vt/vt.c:2773
 do_con_write drivers/tty/vt/vt.c:2541 [inline]
 con_write+0x46/0xd0 drivers/tty/vt/vt.c:3110
 process_output_block drivers/tty/n_tty.c:593 [inline]
 n_tty_write+0x3f9/0x1140 drivers/tty/n_tty.c:2331
 do_tty_write drivers/tty/tty_io.c:960 [inline]
 tty_write+0x458/0x7a0 drivers/tty/tty_io.c:1044
 __vfs_write+0x114/0x810 fs/read_write.c:485
 vfs_write+0x20c/0x560 fs/read_write.c:549
 ksys_write+0x14f/0x2d0 fs/read_write.c:599
 __do_sys_write fs/read_write.c:611 [inline]
 __se_sys_write fs/read_write.c:608 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:608
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4404f9
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 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff20248c18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004404f9
RDX: 0000000000000078 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401de0
R13: 0000000000401e70 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: 000000010000000e
---[ end trace 83b6ec87c4d77f4a ]---
RIP: 0010:memset16 arch/x86/include/asm/string_64.h:43 [inline]
RIP: 0010:scr_memsetw include/linux/vt_buffer.h:36 [inline]
RIP: 0010:insert_char+0x23d/0x450 drivers/tty/vt/vt.c:840
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 01 0f 8e 32 01 00 00 d1 eb 41 0f b7 85 c8 03 00 00 4c 89 ff 89 d9 <f3> 66 ab 49 8d bd 78 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89
RSP: 0018:ffff888092647728 EFLAGS: 00010202
RAX: 0000000000000720 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 1ffff11012078591 RSI: 000000010000000e RDI: 000000010000000e
RBP: ffff888092647770 R08: ffff88807fda4700 R09: 0000000000000005
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: 0000000000000000
R13: ffff8880903c28c0 R14: ffff8880903c2bf4 R15: 000000010000000e
FS:  0000000002652880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000002118000 CR3: 000000009177e000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (46):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro
ci2-linux-4-19	2019/12/16 21:58	linux-4.19.y	312017a4	0ae38e44	.config	log	report	syz	C
ci2-linux-4-19	2020/05/16 01:10	linux-4.19.y	258f0cf7	37bccd4e	.config	log	report
ci2-linux-4-19	2020/05/07 22:12	linux-4.19.y	84920cc7	6c70a1c2	.config	log	report
ci2-linux-4-19	2020/05/07 10:27	linux-4.19.y	84920cc7	98cbd87b	.config	log	report
ci2-linux-4-19	2020/05/04 13:21	linux-4.19.y	fdc07232	58ae5e18	.config	log	report
ci2-linux-4-19	2020/05/03 12:45	linux-4.19.y	fdc07232	58ae5e18	.config	log	report
ci2-linux-4-19	2020/05/02 07:47	linux-4.19.y	76567537	bc734e7a	.config	log	report
ci2-linux-4-19	2020/05/01 21:42	linux-4.19.y	76567537	bc734e7a	.config	log	report
ci2-linux-4-19	2020/05/01 08:34	linux-4.19.y	76567537	143a10e9	.config	log	report
ci2-linux-4-19	2020/04/28 05:04	linux-4.19.y	7edd66cf	0ce7569e	.config	log	report
ci2-linux-4-19	2020/02/13 14:38	linux-4.19.y	35766839	e6247653	.config	log	report
ci2-linux-4-19	2020/02/06 13:04	linux-4.19.y	b499cf4b	5be3a391	.config	log	report
ci2-linux-4-19	2020/02/05 13:51	linux-4.19.y	32ee7492	662cf49a	.config	log	report
ci2-linux-4-19	2020/02/05 11:15	linux-4.19.y	32ee7492	93e5e335	.config	log	report
ci2-linux-4-19	2020/02/05 08:37	linux-4.19.y	32ee7492	93e5e335	.config	log	report
ci2-linux-4-19	2020/02/05 04:38	linux-4.19.y	32ee7492	93e5e335	.config	log	report
ci2-linux-4-19	2020/02/03 20:03	linux-4.19.y	32ee7492	93e5e335	.config	log	report
ci2-linux-4-19	2020/01/29 16:37	linux-4.19.y	7cdefde3	5ed23f9a	.config	log	report
ci2-linux-4-19	2020/01/29 15:39	linux-4.19.y	88d6de67	5ed23f9a	.config	log	report
ci2-linux-4-19	2020/01/16 12:11	linux-4.19.y	db5b9190	3de7aabb	.config	log	report
ci2-linux-4-19	2020/01/15 20:43	linux-4.19.y	db5b9190	f9b69507	.config	log	report
ci2-linux-4-19	2020/01/15 20:36	linux-4.19.y	db5b9190	f9b69507	.config	log	report
ci2-linux-4-19	2020/01/15 18:52	linux-4.19.y	db5b9190	f9b69507	.config	log	report
ci2-linux-4-19	2020/01/11 12:30	linux-4.19.y	cb1f9a16	4c04afaa	.config	log	report
ci2-linux-4-19	2020/01/10 07:25	linux-4.19.y	cb1f9a16	4de4e9f0	.config	log	report
ci2-linux-4-19	2020/01/09 11:21	linux-4.19.y	cb1f9a16	ddc3e859	.config	log	report
ci2-linux-4-19	2020/01/03 11:21	linux-4.19.y	c7ecf3e3	9dcc1191	.config	log	report
ci2-linux-4-19	2019/12/31 17:46	linux-4.19.y	c7ecf3e3	25a0186e	.config	log	report
ci2-linux-4-19	2019/12/31 05:33	linux-4.19.y	672481c2	7f117e28	.config	log	report
ci2-linux-4-19	2019/12/30 16:47	linux-4.19.y	672481c2	6b36d338	.config	log	report
ci2-linux-4-19	2019/12/28 10:54	linux-4.19.y	672481c2	af6b8ef8	.config	log	report
ci2-linux-4-19	2019/12/27 01:54	linux-4.19.y	672481c2	be5c2c81	.config	log	report
ci2-linux-4-19	2019/12/26 02:56	linux-4.19.y	672481c2	be5c2c81	.config	log	report
ci2-linux-4-19	2019/12/25 23:56	linux-4.19.y	672481c2	be5c2c81	.config	log	report
ci2-linux-4-19	2019/12/23 12:01	linux-4.19.y	672481c2	be5c2c81	.config	log	report
ci2-linux-4-19	2019/12/23 11:15	linux-4.19.y	672481c2	be5c2c81	.config	log	report
ci2-linux-4-19	2019/12/21 03:29	linux-4.19.y	7d120bf2	bc586918	.config	log	report
ci2-linux-4-19	2019/12/21 02:56	linux-4.19.y	7d120bf2	bc586918	.config	log	report
ci2-linux-4-19	2019/12/20 14:14	linux-4.19.y	7d120bf2	34011c05	.config	log	report
ci2-linux-4-19	2019/12/20 04:32	linux-4.19.y	7d120bf2	36650b4b	.config	log	report
ci2-linux-4-19	2019/12/18 19:04	linux-4.19.y	7d120bf2	79b211f7	.config	log	report
ci2-linux-4-19	2019/12/18 05:02	linux-4.19.y	7d120bf2	64ca0a37	.config	log	report
ci2-linux-4-19	2019/12/17 01:31	linux-4.19.y	312017a4	d13d7958	.config	log	report
ci2-linux-4-19	2019/12/16 09:29	linux-4.19.y	312017a4	0ae38e44	.config	log	report
ci2-linux-4-19	2019/12/14 06:32	linux-4.19.y	312017a4	eef6e580	.config	log	report
ci2-linux-4-19	2019/12/07 20:09	linux-4.19.y	fb683b5e	1508f453	.config	log	report