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

KASAN: vmalloc-out-of-bounds Write in sys_imageblit
Status: upstream: reported on 2019/12/10 16:38
Reported-by: syzbot+26dc38a00dc05118a4e6@syzkaller.appspotmail.com
First crash: 68d, last: 33d

Sample crash report:

==================================================================
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 ffffc900091a1000 by task syz-executor.0/28284

CPU: 0 PID: 28284 Comm: syz-executor.0 Not tainted 5.5.0-rc6-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: 0033:0x45afd9
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:00007ff705a1fc88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000072bf00 RCX: 000000000045afd9
RDX: 0000000020001900 RSI: 0000000000004b61 RDI: 000000000000000c
RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff705a206d4
R13: 00000000004abfbb R14: 00000000006eff00 R15: 00000000ffffffff


Memory state around the buggy address:
 ffffc900091a0f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900091a0f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc900091a1000: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
                   ^
 ffffc900091a1080: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
 ffffc900091a1100: f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9 f9
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Maintainers
ci-qemu-upstream	2020/01/14 20:18	upstream	452424cd	fa12bd3c	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream	2020/01/14 19:54	upstream	452424cd	fa12bd3c	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream	2020/01/12 16:34	upstream	6327edce	53faa9fe	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream	2019/12/20 03:35	upstream	7e0165b2	36650b4b	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream	2019/12/17 10:41	upstream	ea200dec	2b31345f	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream	2019/12/10 15:24	upstream	6794862a	4b83c8fb	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream-386	2019/12/21 17:04	upstream	62104694	bc586918	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
ci-qemu-upstream-386	2019/12/20 16:04	upstream	7e0165b2	aa56acc6	.config	log	report	b.zolnierkie@samsung.com, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org