BUG: unable to handle kernel paging request in vga16fb_imageblit

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 672481c2 Linux 4.19.91
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14b7398ee00000
kernel config: https://syzkaller.appspot.com/x/.config?x=445a712574d168a6
dashboard link: https://syzkaller.appspot.com/bug?extid=7c566d88d31074e66425
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+7c566d...@syzkaller.appspotmail.com

BUG: unable to handle kernel paging request at ffff8880fffb8c04
PGD ba01067 P4D ba01067 PUD 0
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 22658 Comm: syz-executor.5 Not tainted 4.19.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:writeb arch/x86/include/asm/io.h:65 [inline]
RIP: 0010:vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1168 [inline]
RIP: 0010:vga16fb_imageblit+0xa52/0x2200 drivers/video/fbdev/vga16fb.c:1260
Code: df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0
7c 09 84 d2 74 05 e8 46 e2 1a fe 41 8b 45 14 48 8b 4d c8 <88> 01 0f ae e8
8a 01 b8 05 00 00 00 ba ce 03 00 00 ee 48 c7 c2 50
RSP: 0018:ffff8880532ff498 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000007 RCX: ffff8880fffb8c04
RDX: 0000000000000000 RSI: ffffffff8387f516 RDI: ffff8880532ff654
RBP: ffff8880532ff530 R08: ffff888046b42300 R09: 0000000000000004
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: ffff8880532ff644
R13: ffff8880532ff640 R14: ffff88821970c560 R15: 0000000000000001
FS: 00007f8c86c47700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8880fffb8c04 CR3: 0000000082434000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
bit_putcs+0x9a3/0xf10 drivers/video/fbdev/core/bitblit.c:188
fbcon_putcs+0x42b/0x4f0 drivers/video/fbdev/core/fbcon.c:1320
con_flush drivers/tty/vt/vt.c:2522 [inline]
do_con_write.part.0+0xeb9/0x1eb0 drivers/tty/vt/vt.c:2775
do_con_write drivers/tty/vt/vt.c:3121 [inline]
con_put_char+0xfa/0x110 drivers/tty/vt/vt.c:3120
tty_put_char+0xc5/0x160 drivers/tty/tty_io.c:2887
do_output_char+0x15c/0x880 drivers/tty/n_tty.c:486
process_output drivers/tty/n_tty.c:512 [inline]
n_tty_write+0x4b5/0x1140 drivers/tty/n_tty.c:2343
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: 0033:0x45a919
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8c86c46c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a919
RDX: 00000000000002c1 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f8c86c476d4
R13: 00000000004cbd7a R14: 00000000004e5b48 R15: 00000000ffffffff
Modules linked in:
CR2: ffff8880fffb8c04
---[ end trace 25f67747c136a174 ]---
RIP: 0010:writeb arch/x86/include/asm/io.h:65 [inline]
RIP: 0010:vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1168 [inline]
RIP: 0010:vga16fb_imageblit+0xa52/0x2200 drivers/video/fbdev/vga16fb.c:1260
Code: df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0
7c 09 84 d2 74 05 e8 46 e2 1a fe 41 8b 45 14 48 8b 4d c8 <88> 01 0f ae e8
8a 01 b8 05 00 00 00 ba ce 03 00 00 ee 48 c7 c2 50
RSP: 0018:ffff8880532ff498 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000007 RCX: ffff8880fffb8c04
RDX: 0000000000000000 RSI: ffffffff8387f516 RDI: ffff8880532ff654
RBP: ffff8880532ff530 R08: ffff888046b42300 R09: 0000000000000004
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: ffff8880532ff644
R13: ffff8880532ff640 R14: ffff88821970c560 R15: 0000000000000001
FS: 00007f8c86c47700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8880fffb8c04 CR3: 0000000082434000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.