syzbot


KASAN: vmalloc-out-of-bounds Write in imageblit (4)

Status: upstream: reported C repro on 2024/08/21 10:13
Subsystems: fbdev
[Documentation on labels]
Reported-by: syzbot+c4b7aa0513823e2ea880@syzkaller.appspotmail.com
Fix commit: af0db3c1f898 fbdev: Fix vmalloc out-of-bounds write in fast_imageblit
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm]
First crash: 376d, last: 17m
Discussions (9)
Title Replies (including bot) Last reply
[PATCH] fbdev: Fix vmalloc out-of-bounds write in fast_imageblit 2 (2) 2025/08/02 19:30
[syzbot] [fbdev?] KASAN: vmalloc-out-of-bounds Write in imageblit (4) 0 (3) 2025/07/31 16:57
[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] Monthly fbdev report (May 2025) 0 (1) 2025/05/12 06:34
[syzbot] Monthly fbdev report (Apr 2025) 0 (1) 2025/04/10 10:47
[syzbot] Monthly fbdev report (Mar 2025) 0 (1) 2025/03/09 12:42
[syzbot] Monthly fbdev report (Feb 2025) 0 (1) 2025/02/06 09:15
[syzbot] Monthly fbdev report (Dec 2024) 0 (1) 2024/12/02 12:47
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 fbdev 23 C 104 1402d 1695d 20/29 fixed on 2021/11/10 00:50
upstream KASAN: vmalloc-out-of-bounds Write in imageblit (3) fbdev 23 2 765d 761d 0/29 auto-obsoleted due to no activity on 2023/10/23 10:50
upstream KASAN: vmalloc-out-of-bounds Write in imageblit (2) fbdev 23 C done 701 1090d 1378d 22/29 fixed on 2023/02/24 13:50
upstream KASAN: vmalloc-out-of-bounds Write in sys_imageblit fbdev 23 C 91 1720d 2088d 0/29 auto-obsoleted due to no activity on 2022/12/09 01:09
upstream BUG: unable to handle kernel paging request in sys_imageblit fbdev 8 syz 16 1717d 2088d 0/29 auto-obsoleted due to no activity on 2022/08/31 01:46
upstream KASAN: stack-out-of-bounds Write in sys_imageblit fbdev 23 2 1766d 1864d 0/29 auto-closed as invalid on 2021/02/24 10:13
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/07/31 16:57 21m sravankumarlpu@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git c7fb1692dc0139f95bd4131d3d5fa5eba2ba569e OK log

Sample crash report:
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000001
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
 </TASK>
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
BUG: KASAN: vmalloc-out-of-bounds in sys_imageblit+0x1ec6/0x2b00 drivers/video/fbdev/core/sysimgblt.c:326
Write of size 4 at addr ffffc90001c41000 by task syz-executor161/5103

CPU: 0 UID: 0 PID: 5103 Comm: syz-executor161 Not tainted 6.11.0-rc6-syzkaller-00048-gc7fb1692dc01 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 fast_imageblit drivers/video/fbdev/core/sysimgblt.c:257 [inline]
 sys_imageblit+0x1ec6/0x2b00 drivers/video/fbdev/core/sysimgblt.c:326
 drm_fbdev_shmem_defio_imageblit+0x2e/0x100 drivers/gpu/drm/drm_fbdev_shmem.c:39
 bit_putcs+0x18ba/0x1db0
 fbcon_putcs+0x255/0x390 drivers/video/fbdev/core/fbcon.c:1288
 do_update_region+0x396/0x450 drivers/tty/vt/vt.c:619
 redraw_screen+0x902/0xe90 drivers/tty/vt/vt.c:971
 con2fb_init_display drivers/video/fbdev/core/fbcon.c:794 [inline]
 set_con2fb_map+0xa6c/0x10a0 drivers/video/fbdev/core/fbcon.c:865
 fbcon_set_con2fb_map_ioctl+0x207/0x320 drivers/video/fbdev/core/fbcon.c:3092
 do_fb_ioctl+0x38f/0x7b0 drivers/video/fbdev/core/fb_chrdev.c:138
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feb9b353729
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1a 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffde9b9f968 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffde9b9f980 RCX: 00007feb9b353729
RDX: 00000000200000c0 RSI: 0000000000004610 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007ffde9b9f707 R09: 00000000000000a0
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000001
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
 </TASK>

The buggy address belongs to the virtual mapping at
 [ffffc90001941000, ffffc90001c42000) created by:
 drm_gem_shmem_vmap+0x3ac/0x630 drivers/gpu/drm/drm_gem_shmem_helper.c:343

Memory state around the buggy address:
 ffffc90001c40f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90001c40f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90001c41000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                   ^
 ffffc90001c41080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90001c41100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (3676):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/05 01:05 upstream c7fb1692dc01 dfbe2ed4 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 16:52 upstream 07d9df80082b bee60a83 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 09:33 upstream 07d9df80082b bee60a83 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 04:26 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 01:06 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 19:23 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 12:24 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 08:18 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 04:56 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 02:15 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 00:34 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 14:38 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 12:07 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 00:29 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 21:42 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 05:01 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/24 22:18 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/24 15:51 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto KASAN: vmalloc-out-of-bounds Write in imageblit
2025/07/13 16:48 upstream 3f31a806a62e 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 11:08 upstream 07d9df80082b bee60a83 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 06:09 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 12:19 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 11:15 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 03:54 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 23:18 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 20:57 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 17:58 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 16:35 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 10:32 upstream fab1beda7597 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 06:27 upstream b6add54ba618 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 03:01 upstream b6add54ba618 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 01:58 upstream b6add54ba618 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 22:54 upstream b6add54ba618 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 20:18 upstream b6add54ba618 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 17:26 upstream 1b237f190eb3 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 14:28 upstream 1b237f190eb3 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 11:58 upstream 1b237f190eb3 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 10:43 upstream 1b237f190eb3 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 08:27 upstream 1b237f190eb3 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 02:58 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 02:44 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/25 01:03 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/24 20:29 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/24 17:01 upstream 69fd6b99b8f8 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/04 12:07 upstream d2eedaa3909b abdcb213 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Write in imageblit
2024/08/17 05:01 upstream 670c12ce09a8 e1c76ab2 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/28 03:24 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 13:32 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/26 22:14 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/24 14:20 upstream 8d245acc1e88 bf27483f .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Write in imageblit
2025/08/27 06:46 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto BUG: unable to handle kernel paging request in imageblit
2025/08/28 02:29 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: vmalloc-out-of-bounds Read in imageblit
2025/08/27 15:29 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream BUG: unable to handle kernel paging request in imageblit
2025/08/26 19:53 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: stack-out-of-bounds Write in imageblit
2025/08/27 20:25 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 BUG: unable to handle kernel paging request in imageblit
2025/07/26 02:43 upstream 2942242dde89 fb8f743d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: vmalloc-out-of-bounds Read in imageblit
* Struck through repros no longer work on HEAD.