KASAN: vmalloc-out-of-bounds Write in sys_imageblit

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 6794862a Merge tag 'for-5.5-rc1-kconfig-tag' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17f407f2e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=79f79de2a27d3e3d
dashboard link: https://syzkaller.appspot.com/bug?extid=26dc38a00dc05118a4e6
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+26dc38...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit
drivers/video/fbdev/core/sysimgblt.c:229 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x117f/0x1240
drivers/video/fbdev/core/sysimgblt.c:275
Write of size 4 at addr ffffc90008de1000 by task syz-executor.3/19698

CPU: 0 PID: 19698 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS
rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
print_address_description.constprop.0.cold+0x5/0x30b mm/kasan/report.c:374
__kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
kasan_report+0x12/0x20 mm/kasan/common.c:639
__asan_report_store4_noabort+0x17/0x20 mm/kasan/generic_report.c:139
fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]
sys_imageblit+0x117f/0x1240 drivers/video/fbdev/core/sysimgblt.c:275
drm_fb_helper_sys_imageblit+0x21/0x180 drivers/gpu/drm/drm_fb_helper.c:768
bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
bit_putcs+0x9a3/0xf10 drivers/video/fbdev/core/bitblit.c:188
fbcon_putcs+0x33c/0x3e0 drivers/video/fbdev/core/fbcon.c:1353
do_update_region+0x42b/0x6f0 drivers/tty/vt/vt.c:677
invert_screen+0x2da/0x650 drivers/tty/vt/vt.c:794
highlight drivers/tty/vt/selection.c:53 [inline]
clear_selection drivers/tty/vt/selection.c:81 [inline]
clear_selection+0x59/0x70 drivers/tty/vt/selection.c:77
vc_do_resize+0x1163/0x1460 drivers/tty/vt/vt.c:1200
vc_resize+0x4d/0x60 drivers/tty/vt/vt.c:1304
fbcon_do_set_font+0x4a6/0x960 drivers/video/fbdev/core/fbcon.c:2599
fbcon_set_font+0x72e/0x860 drivers/video/fbdev/core/fbcon.c:2696
con_font_set drivers/tty/vt/vt.c:4538 [inline]
con_font_op+0xe30/0x1270 drivers/tty/vt/vt.c:4603
vt_ioctl+0xd2e/0x26d0 drivers/tty/vt/vt_ioctl.c:913
tty_ioctl+0xa37/0x14f0 drivers/tty/tty_io.c:2660
vfs_ioctl fs/ioctl.c:47 [inline]
file_ioctl fs/ioctl.c:545 [inline]
do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
__do_sys_ioctl fs/ioctl.c:756 [inline]
__se_sys_ioctl fs/ioctl.c:754 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a7c9
Code: bd b1 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 8b b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fcfa0ba6c88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000072bf00 RCX: 000000000045a7c9
RDX: 0000000020000140 RSI: 0000000000004b61 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fcfa0ba76d4
R13: 00000000004ab60f R14: 00000000006ede60 R15: 00000000ffffffff


Memory state around the buggy address:
ffffc90008de0f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc90008de0f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffffc90008de1000: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
^
ffffc90008de1080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90008de1100: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
==================================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
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[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 435faf5c Merge tag 'riscv-for-linus-5.8-mw0' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1519d83e100000
kernel config: https://syzkaller.appspot.com/x/.config?x=3dbb617b9c2a5bdf

dashboard link: https://syzkaller.appspot.com/bug?extid=26dc38a00dc05118a4e6
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17fbd189100000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+26dc38...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]

BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x1181/0x1240 drivers/video/fbdev/core/sysimgblt.c:275
Write of size 4 at addr ffffc90009c1b040 by task syz-executor.0/9196

CPU: 2 PID: 9196 Comm: syz-executor.0 Not tainted 5.7.0-syzkaller #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]

dump_stack+0x188/0x20d lib/dump_stack.c:118
print_address_description.constprop.0.cold+0x5/0x413 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]
sys_imageblit+0x1181/0x1240 drivers/video/fbdev/core/sysimgblt.c:275
drm_fb_helper_sys_imageblit+0x1c/0x180 drivers/gpu/drm/drm_fb_helper.c:747
bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
bit_putcs+0x8d0/0xd60 drivers/video/fbdev/core/bitblit.c:188
fbcon_putcs+0x345/0x3f0 drivers/video/fbdev/core/fbcon.c:1362
do_update_region+0x398/0x630 drivers/tty/vt/vt.c:683
invert_screen+0x2a7/0x600 drivers/tty/vt/vt.c:800
highlight drivers/tty/vt/selection.c:57 [inline]
clear_selection drivers/tty/vt/selection.c:84 [inline]
clear_selection+0x55/0x70 drivers/tty/vt/selection.c:80
vc_do_resize+0xff3/0x1370 drivers/tty/vt/vt.c:1230
fbcon_do_set_font+0x4a0/0x950 drivers/video/fbdev/core/fbcon.c:2608
fbcon_set_font+0x732/0x870 drivers/video/fbdev/core/fbcon.c:2705
con_font_set drivers/tty/vt/vt.c:4571 [inline]
con_font_op+0xd65/0x1160 drivers/tty/vt/vt.c:4636
vt_ioctl+0x1740/0x2640 drivers/tty/vt/vt_ioctl.c:980
tty_ioctl+0xedc/0x1440 drivers/tty/tty_io.c:2656
vfs_ioctl fs/ioctl.c:47 [inline]
ksys_ioctl+0x11a/0x180 fs/ioctl.c:771
__do_sys_ioctl fs/ioctl.c:780 [inline]
__se_sys_ioctl fs/ioctl.c:778 [inline]
__x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:778
do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45c879
Code: 1d b2 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 eb b1 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fb46427fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000074bf00 RCX: 000000000045c879
RDX: 0000000020000080 RSI: 0000000000004b72 RDI: 0000000000000003
RBP: 00000000006fae40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb4642806d4
R13: 000000000000037a R14: 00000000006ecfc0 R15: 00000000004ace26

Memory state around the buggy address:

ffffc90009c1af00: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90009c1af80: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
>ffffc90009c1b000: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
^
ffffc90009c1b080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
ffffc90009c1b100: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
==================================================================

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: c85fb28b Merge tag 'arm64-fixes' of git://git.kernel.org/p..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17406d70500000
kernel config: https://syzkaller.appspot.com/x/.config?x=140446ac2aa637e5
dashboard link: https://syzkaller.appspot.com/bug?extid=26dc38a00dc05118a4e6
compiler: gcc (GCC) 10.1.0-syz 20200507
userspace arch: i386
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14788d70500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15158ee0500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+26dc38...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]

BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x117f/0x1290 drivers/video/fbdev/core/sysimgblt.c:275
Write of size 4 at addr ffffc90009911000 by task syz-executor045/8761

CPU: 0 PID: 8761 Comm: syz-executor045 Not tainted 5.9.0-rc8-syzkaller #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]

dump_stack+0x198/0x1fd lib/dump_stack.c:118
print_address_description.constprop.0.cold+0x5/0x497 mm/kasan/report.c:383

__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
fast_imageblit drivers/video/fbdev/core/sysimgblt.c:229 [inline]

sys_imageblit+0x117f/0x1290 drivers/video/fbdev/core/sysimgblt.c:275
drm_fb_helper_sys_imageblit+0x1c/0x180 drivers/gpu/drm/drm_fb_helper.c:767
bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline]
bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188
fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1308
do_update_region+0x399/0x630 drivers/tty/vt/vt.c:675
redraw_screen+0x658/0x790 drivers/tty/vt/vt.c:1034
fbcon_modechanged+0x593/0x6d0 drivers/video/fbdev/core/fbcon.c:2714
fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:2759
do_fb_ioctl+0x62e/0x690 drivers/video/fbdev/core/fbmem.c:1106
fb_compat_ioctl+0x17c/0xc30 drivers/video/fbdev/core/fbmem.c:1311
__do_compat_sys_ioctl+0x1d3/0x230 fs/ioctl.c:842
do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline]
__do_fast_syscall_32+0x60/0x90 arch/x86/entry/common.c:137
do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:160
entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f58549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f7f531dc EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004601
RDX: 0000000020000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Memory state around the buggy address:

ffffc90009910f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffc90009910f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90009911000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
^
ffffc90009911080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
ffffc90009911100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

[syzbot]

Auto-closing this bug as obsolete.
No recent activity, existing reproducers are no longer triggering the issue.