KASAN: global-out-of-bounds Read in uevent_store

Status: upstream: reported C repro on 2026/08/24 05:35
Subsystems: kernel
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+d164947c037324221043@syzkaller.appspotmail.com
First crash: 49d, last: 11d
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
6dfc0397 repro-c 💥 KASAN: global-out-of-bounds Read in uevent_store 2026/08/26 14:06 2026/08/26 15:48 2026/08/26 20:52 a2b77b9e
527aad43 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ KASAN: global-out-of-bounds Read in uevent_store 2026/08/21 01:02 2026/08/21 01:02 2026/08/21 01:58 1e72964b
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[PATCH] kobject_uevent: fix OOB read in kobject_action_type() 3 (3) 2026/10/05 10:26
[syzbot] [kernel?] KASAN: global-out-of-bounds Read in uevent_store 3 (7) 2026/08/30 06:07
▶ ▼ Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/08/24 07:11 18m jeffinphilip14@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 9d2ed026f031 OK job log log

Sample crash report:
==================================================================
BUG: KASAN: global-out-of-bounds in kobject_action_type lib/kobject_uevent.c:86 [inline]
BUG: KASAN: global-out-of-bounds in kobject_synth_uevent+0x79d/0x7d0 lib/kobject_uevent.c:200
Read of size 1 at addr ffffffff8d7255ab by task syz.0.17/5921

CPU: 0 UID: 0 PID: 5921 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 kobject_action_type lib/kobject_uevent.c:86 [inline]
 kobject_synth_uevent+0x79d/0x7d0 lib/kobject_uevent.c:200
 uevent_store+0x46/0x90 drivers/base/bus.c:723
 drv_attr_store+0x74/0xb0 drivers/base/bus.c:125
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6af/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f636219e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffeedeab68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6362425fa0 RCX: 00007f636219e159
RDX: 000000000000018b RSI: 0000200000000ac0 RDI: 0000000000000003
RBP: 00007f636223506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6362425fac R14: 00007f6362425fa0 R15: 00007f6362425fa0
 </TASK>

The buggy address belongs to the variable:
 uevent_helper_sysctl_table+0x22b/0x2a0

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xd725
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea000035c948 ffffea000035c948 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff8d725480: f9 f9 f9 f9 07 f9 f9 f9 f9 f9 f9 f9 05 f9 f9 f9
 ffffffff8d725500: f9 f9 f9 f9 07 f9 f9 f9 f9 f9 f9 f9 00 f9 f9 f9
>ffffffff8d725580: f9 f9 f9 f9 05 f9 f9 f9 f9 f9 f9 f9 07 f9 f9 f9
                                  ^
 ffffffff8d725600: f9 f9 f9 f9 00 00 00 00 00 00 00 00 f9 f9 f9 f9
 ffffffff8d725680: 00 00 00 04 f9 f9 f9 f9 00 00 02 f9 f9 f9 f9 f9
==================================================================

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/19 17:04 upstream 40288c9206c1 853b104b .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/09/14 09:45 upstream 704340f1cd0d 70a60e12 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/09/09 00:40 upstream 5acbae5f7eb3 8387c273 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/09/12 14:41 upstream 50d05c7c76c9 70a60e12 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/09/07 03:23 upstream 1fc5a74b108f 4f7b22a0 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/09/28 08:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 a3c7249d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: global-out-of-bounds Read in uevent_store
2026/09/27 13:59 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci e8e60d3ddd25 a3c7249d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: global-out-of-bounds Read in uevent_store
2026/08/30 06:07 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci f1b8fa82cab7 2f52988a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 20:42 upstream 9d2ed026f031 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 20:28 upstream 9d2ed026f031 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 20:10 upstream 9d2ed026f031 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 19:57 upstream 9d2ed026f031 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/25 06:04 upstream 66498c75b4f8 614e416a .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/08/21 00:40 upstream 9d2ed026f031 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/08/21 00:27 upstream 9d2ed026f031 1e72964b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 19:36 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 19:36 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/20 19:36 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream KASAN: global-out-of-bounds Read in uevent_store
2026/08/21 00:14 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/08/21 00:14 upstream 9d2ed026f031 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 KASAN: global-out-of-bounds Read in uevent_store
2026/08/30 05:15 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci f1b8fa82cab7 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 KASAN: global-out-of-bounds Read in uevent_store
* Struck through repros no longer work on HEAD.