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

Status: upstream: reported on 2025/05/28 09:22
Subsystems: fbdev
[Documentation on labels]
Reported-by: syzbot+7a63ce155648954e749b@syzkaller.appspotmail.com
First crash: 200d, last: 11h20m
▶ ▼ Discussions (5)
Title Replies (including bot) Last reply
[syzbot] Monthly fbdev report (Sep 2025) 0 (1) 2025/09/12 21:33
[syzbot] Monthly fbdev report (Aug 2025) 0 (1) 2025/08/12 12:44
[syzbot] Monthly fbdev report (Jul 2025) 0 (1) 2025/07/14 07:22
[syzbot] Monthly fbdev report (Jun 2025) 0 (1) 2025/06/11 07:46
[syzbot] [fbdev?] KASAN: vmalloc-out-of-bounds Write in fillrect 0 (1) 2025/05/28 09:22

Sample crash report:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline]
BUG: KASAN: vmalloc-out-of-bounds in bitfill drivers/video/fbdev/core/fb_fillrect.h:133 [inline]
BUG: KASAN: vmalloc-out-of-bounds in fb_fillrect_static drivers/video/fbdev/core/fb_fillrect.h:219 [inline]
BUG: KASAN: vmalloc-out-of-bounds in fb_fillrect drivers/video/fbdev/core/fb_fillrect.h:278 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_fillrect+0x15d4/0x17b0 drivers/video/fbdev/core/sysfillrect.c:24
Write of size 8 at addr ffffc90003799600 by task syz.3.868/10271

CPU: 0 UID: 0 PID: 10271 Comm: syz.3.868 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 fb_write_offset drivers/video/fbdev/core/sysmem.h:30 [inline]
 bitfill drivers/video/fbdev/core/fb_fillrect.h:133 [inline]
 fb_fillrect_static drivers/video/fbdev/core/fb_fillrect.h:219 [inline]
 fb_fillrect drivers/video/fbdev/core/fb_fillrect.h:278 [inline]
 sys_fillrect+0x15d4/0x17b0 drivers/video/fbdev/core/sysfillrect.c:24
 drm_fbdev_shmem_defio_fillrect+0x22/0x140 drivers/gpu/drm/drm_fbdev_shmem.c:38
 bit_clear+0x17d/0x220 drivers/video/fbdev/core/bitblit.c:73
 __fbcon_clear+0x603/0x720 drivers/video/fbdev/core/fbcon.c:1303
 csi_X drivers/tty/vt/vt.c:1585 [inline]
 csi_ECMA drivers/tty/vt/vt.c:2615 [inline]
 do_con_trol drivers/tty/vt/vt.c:2733 [inline]
 do_con_write+0x401e/0x8290 drivers/tty/vt/vt.c:3228
 con_write+0x23/0xb0 drivers/tty/vt/vt.c:3565
 process_output_block drivers/tty/n_tty.c:561 [inline]
 n_tty_write+0x41e/0x11e0 drivers/tty/n_tty.c:2377
 iterate_tty_write drivers/tty/tty_io.c:1006 [inline]
 file_tty_write.constprop.0+0x503/0x9b0 drivers/tty/tty_io.c:1081
 tty_write drivers/tty/tty_io.c:1102 [inline]
 redirected_tty_write drivers/tty/tty_io.c:1125 [inline]
 redirected_tty_write+0xd4/0x150 drivers/tty/tty_io.c:1105
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x7d3/0x11d0 fs/read_write.c:686
 ksys_write+0x12a/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a9f78efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5a9d9b4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5a9f9e6180 RCX: 00007f5a9f78efc9
RDX: 00000000000000a5 RSI: 0000200000000340 RDI: 0000000000000008
RBP: 00007f5a9f811f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a9f9e6218 R14: 00007f5a9f9e6180 R15: 00007ffe85ed2a88
 </TASK>

The buggy address belongs to a vmalloc virtual mapping
Memory state around the buggy address:
 ffffc90003799500: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90003799580: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90003799600: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc90003799680: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90003799700: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (116):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/28 15:36 upstream fd57572253bc fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/24 10:19 upstream cec1e6e5d1ab 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/23 07:43 upstream cec1e6e5d1ab 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/23 03:17 upstream cec1e6e5d1ab 0ac7291c .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/13 09:04 upstream 22f20375f5b7 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/06 19:08 upstream d1d10cea0895 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/05/20 18:50 upstream a5806cd506af b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in fillrect
2025/11/02 12:18 upstream 691d401c7e0e 2c50b6a9 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/11/01 08:24 upstream ba36dd5ee6fd 2c50b6a9 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/11/01 05:05 upstream b909d77359b8 2c50b6a9 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/29 12:51 upstream e53642b87a4f fd2207e7 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/29 00:35 upstream 8eefed8f65cc fd2207e7 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/25 10:05 upstream d2818517e348 c0460fcd .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/24 22:44 upstream d2818517e348 c0460fcd .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/23 22:47 upstream ab431bc39741 c0460fcd .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/23 15:12 upstream 43e9ad0c55a3 c0460fcd .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/23 04:36 upstream dd72c8fcf6d3 c0460fcd .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/22 09:14 upstream 552c50713f27 252fbbad .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/20 09:52 upstream 211ddde0823f 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/20 03:37 upstream d9043c79ba68 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/20 02:19 upstream d9043c79ba68 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/18 19:37 upstream f406055cb18c 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/18 16:47 upstream f406055cb18c 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/18 05:58 upstream 6f3b6e91f720 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/15 04:36 upstream 9b332cece987 b6605ba8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/13 15:25 upstream 3a8660878839 b6605ba8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/13 02:37 upstream 3a8660878839 ff1712fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/12 10:31 upstream 98906f9d850e ff1712fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/12 01:45 upstream 98906f9d850e ff1712fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/10 10:14 upstream 5472d60c129f ff1712fe .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/08 00:24 upstream 971199ad2a0f 7e2882b3 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/05 03:04 upstream cbf33b8e0b36 49379ee0 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/01 08:03 upstream 4b81e2eb9e4d 65a0eece .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/29 21:29 upstream e5f0a698b34e 86341da6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/29 07:01 upstream 8f9736633f8c 001c9061 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/27 09:08 upstream 083fc6d7fa0d 001c9061 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/27 06:02 upstream 083fc6d7fa0d 001c9061 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/25 05:06 upstream 4ea5af085908 0abd0691 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/24 18:40 upstream cec1e6e5d1ab 0abd0691 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/22 09:33 upstream 07e27ad16399 770ff59f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/16 11:45 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/16 04:40 upstream 46a51f4f5eda e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/13 14:06 upstream 22f20375f5b7 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/12 00:42 upstream 02ffd6f89c50 e2beed91 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/10 15:25 upstream 9dd1835ecda5 fdeaa69b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/09/09 07:39 upstream f777d1112ee5 d291dd2d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/04/16 00:23 upstream 1a1d569a75f3 a95239b1 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/30 12:37 upstream e53642b87a4f fd2207e7 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Write in fillrect
2025/06/25 14:33 upstream 7595b66ae9de 26d77996 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Write in fillrect
2025/10/25 22:45 upstream 566771afc7a8 c0460fcd .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: stack-out-of-bounds Write in fillrect
2025/09/24 23:49 upstream 4ea5af085908 0abd0691 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: stack-out-of-bounds Write in fillrect
* Struck through repros no longer work on HEAD.