syzbot


KASAN: vmalloc-out-of-bounds Read in run_irq_workd

Status: upstream: reported syz repro on 2025/08/31 00:33
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+2617fc732430968b45d2@syzkaller.appspotmail.com
First crash: 5d04h, last: 3d01h
Discussions (1)
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[syzbot] [kernel?] KASAN: vmalloc-out-of-bounds Read in run_irq_workd 0 (1) 2025/08/31 00:33

Sample crash report:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in irq_work_run_list kernel/irq_work.c:251 [inline]
BUG: KASAN: vmalloc-out-of-bounds in run_irq_workd+0x116/0x190 kernel/irq_work.c:305
Read of size 8 at addr ffffc90005289090 by task irq_work/1/26

CPU: 1 UID: 0 PID: 26 Comm: irq_work/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 irq_work_run_list kernel/irq_work.c:251 [inline]
 run_irq_workd+0x116/0x190 kernel/irq_work.c:305
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to a vmalloc virtual mapping
Memory state around the buggy address:
 ffffc90005288f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90005289000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>ffffc90005289080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                         ^
 ffffc90005289100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 ffffc90005289180: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/27 18:31 upstream fab1beda7597 e12e5ba4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in run_irq_workd
2025/08/29 02:59 upstream 07d9df80082b 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in run_irq_workd
2025/08/27 00:27 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: vmalloc-out-of-bounds Read in run_irq_workd
* Struck through repros no longer work on HEAD.