BUG: unable to handle kernel paging request in imageblit

From: Hao Sun
Date: Sun Sep 12 2021 - 23:07:15 EST

Hello,

When using Healer to fuzz the Linux kernel, the following crash was triggered.

HEAD commit: ac08b1c68d1b Merge tag 'pci-v5.15-changes'
git tree: upstream
console output:
https://drive.google.com/file/d/1Vvyiebkb1BAbgnM8QXg4XeotLYE7Xrk6/view?usp=sharing
kernel config: https://drive.google.com/file/d/1qrJUXD8ZIeAkg-xojzDpp04v9MtQ8RR6/view?usp=sharing
C reproducer: https://drive.google.com/file/d/1p79Nwcx6l7pC0qLZnbHFvr5FLSR79x0J/view?usp=sharing
Syzlang reproducer:
https://drive.google.com/file/d/1MT6DvJG2lMonmimV6XbED-I_STFMvaFo/view?usp=sharing

If you fix this issue, please add the following tag to the commit:
Reported-by: Hao Sun <sunhao.th@xxxxxxxxx>

BUG: unable to handle page fault for address: ffffc90007731480
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 8c00067 P4D 8c00067 PUD 8d63067 PMD 1026f8067 PTE 0
Oops: 0002 [#1] PREEMPT SMP
CPU: 0 PID: 10837 Comm: syz-executor Not tainted 5.14.0+ #15
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]
RIP: 0010:sys_imageblit+0x48c/0x830 drivers/video/fbdev/core/sysimgblt.c:275
Code: 04 41 0f be 5d 00 83 fd 1f 0f 87 75 03 00 00 e8 5a d5 f9 fe 89
e9 8b 44 24 14 d3 fb 23 5c 24 08 41 23 04 9f 33 44 24 04 85 ed <41> 89
44 24 fc 75 b9 e8 38 d5 f9 fe 49 83 c5 01 bd 08 00 00 00 e8
RSP: 0018:ffffc9000928f890 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000040000 RSI: ffffffff823dbcd6 RDI: ffffc9000928f9f0
RBP: 0000000000000007 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000002 R12: ffffc90007731484
R13: ffff88810496f13c R14: ffffc90007731500 R15: ffffffff849e52c0
FS: 00007fef7bf33700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90007731480 CR3: 000000001ef3e000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
drm_fb_helper_sys_imageblit+0x18/0x40 drivers/gpu/drm/drm_fb_helper.c:794
drm_fbdev_fb_imageblit+0x4b/0xa0 drivers/gpu/drm/drm_fb_helper.c:2276
bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
bit_putcs+0x33c/0x590 drivers/video/fbdev/core/bitblit.c:188
fbcon_putcs+0x13f/0x1a0 drivers/video/fbdev/core/fbcon.c:1296
do_update_region+0x163/0x230 drivers/tty/vt/vt.c:676
invert_screen+0x105/0x280 drivers/tty/vt/vt.c:800
highlight drivers/tty/vt/selection.c:57 [inline]
clear_selection+0x48/0x60 drivers/tty/vt/selection.c:84
vc_do_resize+0x60b/0x6f0 drivers/tty/vt/vt.c:1257
fbcon_do_set_font+0x188/0x2a0 drivers/video/fbdev/core/fbcon.c:2397
fbcon_set_font+0x333/0x450 drivers/video/fbdev/core/fbcon.c:2483
con_font_set drivers/tty/vt/vt.c:4666 [inline]
con_font_op+0x238/0x4b0 drivers/tty/vt/vt.c:4710
vt_k_ioctl drivers/tty/vt/vt_ioctl.c:474 [inline]
vt_ioctl+0xd05/0x1890 drivers/tty/vt/vt_ioctl.c:752
tty_ioctl+0x114/0xb00 drivers/tty/tty_io.c:2805
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0xb6/0x100 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x34/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x46a9a9
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fef7bf32c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000078c0a0 RCX: 000000000046a9a9
RDX: 0000000020000080 RSI: 0000000000004b72 RDI: 0000000000000004
RBP: 00000000004e4042 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078c0a0
R13: 0000000000000000 R14: 000000000078c0a0 R15: 00007fff66610a60
Modules linked in:
Dumping ftrace buffer:
(ftrace buffer empty)
CR2: ffffc90007731480
---[ end trace b77be2f6638c5c66 ]---
RIP: 0010:fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]
RIP: 0010:sys_imageblit+0x48c/0x830 drivers/video/fbdev/core/sysimgblt.c:275
Code: 04 41 0f be 5d 00 83 fd 1f 0f 87 75 03 00 00 e8 5a d5 f9 fe 89
e9 8b 44 24 14 d3 fb 23 5c 24 08 41 23 04 9f 33 44 24 04 85 ed <41> 89
44 24 fc 75 b9 e8 38 d5 f9 fe 49 83 c5 01 bd 08 00 00 00 e8
RSP: 0018:ffffc9000928f890 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000007
RDX: 0000000000040000 RSI: ffffffff823dbcd6 RDI: ffffc9000928f9f0
RBP: 0000000000000007 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000002 R12: ffffc90007731484
R13: ffff88810496f13c R14: ffffc90007731500 R15: ffffffff849e52c0
FS: 00007fef7bf33700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc90007731480 CR3: 000000001ef3e000 CR4: 0000000000750ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
----------------
Code disassembly (best guess):
0: 04 41 add $0x41,%al
2: 0f be 5d 00 movsbl 0x0(%rbp),%ebx
6: 83 fd 1f cmp $0x1f,%ebp
9: 0f 87 75 03 00 00 ja 0x384
f: e8 5a d5 f9 fe callq 0xfef9d56e
14: 89 e9 mov %ebp,%ecx
16: 8b 44 24 14 mov 0x14(%rsp),%eax
1a: d3 fb sar %cl,%ebx
1c: 23 5c 24 08 and 0x8(%rsp),%ebx
20: 41 23 04 9f and (%r15,%rbx,4),%eax
24: 33 44 24 04 xor 0x4(%rsp),%eax
28: 85 ed test %ebp,%ebp
* 2a: 41 89 44 24 fc mov %eax,-0x4(%r12) <-- trapping instruction
2f: 75 b9 jne 0xffffffea
31: e8 38 d5 f9 fe callq 0xfef9d56e
36: 49 83 c5 01 add $0x1,%r13
3a: bd 08 00 00 00 mov $0x8,%ebp
3f: e8 .byte 0xe8