syzbot


KASAN: out-of-bounds Read in perf_iommu_stop

Status: auto-closed as invalid on 2020/08/30 07:52
Reported-by: syzbot+c5b1640b69902dca8fe8@syzkaller.appspotmail.com
First crash: 788d, last: 788d

Sample crash report:
FAT-fs (loop1): Can't find a valid FAT filesystem
==================================================================
BUG: KASAN: out-of-bounds in perf_iommu_disable_event arch/x86/events/amd/iommu.c:282 [inline]
BUG: KASAN: out-of-bounds in perf_iommu_stop+0x267/0x280 arch/x86/events/amd/iommu.c:339
Read of size 1 at addr ffff8882128f7318 by task syz-executor.1/4376

CPU: 1 PID: 4376 Comm: syz-executor.1 Not tainted 4.14.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 print_address_description.cold+0x7c/0x1e2 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2ae mm/kasan/report.c:393
 perf_iommu_disable_event arch/x86/events/amd/iommu.c:282 [inline]
 perf_iommu_stop+0x267/0x280 arch/x86/events/amd/iommu.c:339
 </IRQ>

The buggy address belongs to the page:
page:ffffea00084a3dc0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x57ffe0000000000()
raw: 057ffe0000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: 0000000000000000 0000000100000001 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8882128f7200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8882128f7280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8882128f7300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                               ^
 ffff8882128f7380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8882128f7400: 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2020/05/02 07:51 linux-4.14.y 050272a0423e bc734e7a .config log report