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

Status: auto-obsoleted due to no activity on 2022/12/09 01:09
Subsystems: fbdev
[Documentation on labels]
Reported-by: syzbot+26dc38a00dc05118a4e6@syzkaller.appspotmail.com
First crash: 2442d, last: 2075d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
KASAN: vmalloc-out-of-bounds Write in sys_imageblit 0 (3) 2020/10/07 07:42
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: vmalloc-out-of-bounds Write in imageblit (6) prio:high fbdev 21 syz, C 7589 now 288d 0/29 upstream: reported C repro on 2025/11/02 21:10
linux-5.15 KASAN: vmalloc-out-of-bounds Write in imageblit 21 11 1d17h 11d 0/3 upstream: reported on 2026/08/06 13:30
linux-6.1 KASAN: vmalloc-out-of-bounds Write in imageblit 21 32 6h13m 10d 0/3 upstream: reported on 2026/08/07 05:50
upstream KASAN: vmalloc-out-of-bounds Write in imageblit (5) fbdev 21 syz, C 1075 292d 343d 29/29 fixed on 2025/10/29 21:02
upstream KASAN: vmalloc-out-of-bounds Write in imageblit (4) fbdev 21 syz, C 3869 347d 726d 29/29 fixed on 2025/09/04 16:57
linux-6.6 KASAN: vmalloc-out-of-bounds Write in imageblit 21 9 3d08h 12d 0/2 upstream: reported on 2026/08/05 13:55
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2022/12/09 00:31 33m retest repro upstream no crash log
2022/12/09 00:31 38m retest repro upstream no crash log
2022/08/31 00:27 21m retest repro upstream no crash log
2022/08/30 23:27 19m retest repro upstream no crash log
2022/08/30 23:27 14m retest repro upstream report log

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/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
==================================================================

Crashes (91):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/07 07:41 upstream c85fb28b6f99 1880b4a9 .config console log report syz C ci-qemu-upstream-386
2020/06/11 23:34 upstream 435faf5c218a 5c25fdab .config console log report syz ci-qemu-upstream
2020/10/07 05:27 upstream c85fb28b6f99 1880b4a9 .config console log report syz ci-qemu-upstream-386
2020/12/11 04:46 upstream 9fca90cf2892 f900b48c .config console log report info ci-qemu-upstream
2020/12/10 11:38 upstream a2f5ea9e314b 2a55c22b .config console log report info ci-qemu-upstream
2020/12/10 10:07 upstream a2f5ea9e314b 2a55c22b .config console log report info ci-qemu-upstream
2020/12/04 19:40 upstream e87297fa080a 20366b87 .config console log report info ci-qemu-upstream
2020/12/02 11:47 upstream 509a15421674 eff43e99 .config console log report info ci-qemu-upstream
2020/12/01 22:38 upstream b65054597872 07bfe8a5 .config console log report info ci-qemu-upstream
2020/11/10 07:55 upstream 407ab579637c cca87986 .config console log report info ci-qemu-upstream
2020/11/10 02:54 upstream 407ab579637c 64069d48 .config console log report info ci-qemu-upstream
2020/11/09 22:56 upstream f8394f232b1e 64069d48 .config console log report info ci-qemu-upstream
2020/11/05 15:24 upstream 4ef8451b3326 64069d48 .config console log report info ci-qemu-upstream
2020/10/23 19:14 upstream 0adc313c4f20 2bb6666c .config console log report info ci-qemu-upstream
2020/09/11 07:49 upstream fffe3ae0ee84 adfb8b4e .config console log report ci-qemu-upstream
2020/09/09 07:27 upstream fffe3ae0ee84 0ea7a887 .config console log report ci-qemu-upstream
2020/09/08 17:15 upstream fffe3ae0ee84 abf9ba4f .config console log report ci-qemu-upstream
2020/09/04 23:53 upstream fffe3ae0ee84 abf9ba4f .config console log report ci-qemu-upstream
2019/12/17 10:41 upstream ea200dec5128 2b31345f .config console log report ci-qemu-upstream
2019/12/10 15:24 upstream 6794862a16ef 4b83c8fb .config console log report ci-qemu-upstream
2020/12/11 22:50 upstream 94801e5c6d46 bca53db9 .config console log report info ci-qemu-upstream-386
2020/11/18 15:53 upstream 0fa8ee0d9ab9 09323409 .config console log report info ci-qemu-upstream-386
2020/11/02 20:55 upstream 495023e4e49e f7362256 .config console log report info ci-qemu-upstream-386
2020/10/27 22:18 upstream ed8780e3f2ec 96e03c1c .config console log report info ci-qemu-upstream-386
2020/10/18 12:53 upstream 9d9af1007bc0 fea47c01 .config console log report info ci-qemu-upstream-386
2020/10/18 01:42 upstream 9d9af1007bc0 fea47c01 .config console log report info ci-qemu-upstream-386
2020/10/13 06:56 upstream 1e6d1d96461e d32b0bbf .config console log report info ci-qemu-upstream-386
2020/10/13 02:00 upstream 1e6d1d96461e d32b0bbf .config console log report info ci-qemu-upstream-386
2020/10/12 22:03 upstream 1e6d1d96461e d32b0bbf .config console log report info ci-qemu-upstream-386
2020/10/11 19:35 upstream 3dd0130f2430 4a77ae0b .config console log report info ci-qemu-upstream-386
2020/10/11 15:52 upstream da690031a5d6 4a77ae0b .config console log report info ci-qemu-upstream-386
2020/10/11 02:06 upstream da690031a5d6 4a77ae0b .config console log report info ci-qemu-upstream-386
2020/10/09 22:33 upstream 8a5f78d98c26 93817d89 .config console log report info ci-qemu-upstream-386
2020/10/09 10:30 upstream 583090b1b823 fa79ed2a .config console log report info ci-qemu-upstream-386
2020/10/08 21:12 upstream 3d006ee42dde 92390980 .config console log report info ci-qemu-upstream-386
2020/10/08 11:01 upstream c85fb28b6f99 92390980 .config console log report info ci-qemu-upstream-386
2020/10/07 11:25 upstream c85fb28b6f99 1880b4a9 .config console log report info ci-qemu-upstream-386
2020/10/07 07:04 upstream c85fb28b6f99 1880b4a9 .config console log report info ci-qemu-upstream-386
2020/10/07 04:04 upstream c85fb28b6f99 1880b4a9 .config console log report info ci-qemu-upstream-386
2020/10/05 02:40 upstream 549738f15da0 5ef9c291 .config console log report info ci-qemu-upstream-386
2020/10/04 14:29 upstream 22fbc037cd32 5ef9c291 .config console log report info ci-qemu-upstream-386
2020/10/04 03:00 upstream 22fbc037cd32 1a3f9408 .config console log report info ci-qemu-upstream-386
2020/09/30 06:51 upstream 02de58b24d2e 8516f6d3 .config console log report info ci-qemu-upstream-386
2020/09/28 22:41 upstream a4d63c3732f1 1b88c6d5 .config console log report info ci-qemu-upstream-386
2020/09/06 15:12 upstream dd9fb9bb3340 abf9ba4f .config console log report ci-qemu-upstream-386
2020/09/04 04:40 upstream e28f0104343d abf9ba4f .config console log report ci-qemu-upstream-386
2020/08/25 20:46 upstream abb3438d69fb 344da168 .config console log report ci-qemu-upstream-386
* Struck through repros no longer work on HEAD.