Messages in this thread | | | Date | Mon, 16 May 2022 07:51:22 -0700 | Subject | Re: [PATCH v2 2/2] exfat: check if cluster num is valid | From | Tadeusz Struk <> |
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On 5/15/22 07:52, Sungjong Seo wrote: >> Syzbot reported slab-out-of-bounds read in exfat_clear_bitmap. >> This was triggered by reproducer calling truncute with size 0, which >> causes the following trace: >> >> BUG: KASAN: slab-out-of-bounds in exfat_clear_bitmap+0x147/0x490 >> fs/exfat/balloc.c:174 Read of size 8 at addr ffff888115aa9508 by task syz- >> executor251/365 >> >> Call Trace: >> __dump_stack lib/dump_stack.c:77 [inline] dump_stack_lvl+0x1e2/0x24b >> lib/dump_stack.c:118 >> print_address_description+0x81/0x3c0 mm/kasan/report.c:233 >> __kasan_report mm/kasan/report.c:419 [inline] >> kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436 >> __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309 >> exfat_clear_bitmap+0x147/0x490 fs/exfat/balloc.c:174 >> exfat_free_cluster+0x25a/0x4a0 fs/exfat/fatent.c:181 >> __exfat_truncate+0x99e/0xe00 fs/exfat/file.c:217 >> exfat_truncate+0x11b/0x4f0 fs/exfat/file.c:243 >> exfat_setattr+0xa03/0xd40 fs/exfat/file.c:339 >> notify_change+0xb76/0xe10 fs/attr.c:336 >> do_truncate+0x1ea/0x2d0 fs/open.c:65 >> >> Add checks to validate if cluster number is within valid range in >> exfat_clear_bitmap() and exfat_set_bitmap() >> >> Cc: Namjae Jeon<linkinjeon@kernel.org> >> Cc: Sungjong Seo<sj1557.seo@samsung.com> >> Cc:linux-fsdevel@vger.kernel.org >> Cc:stable@vger.kernel.org >> Cc:linux-kernel@vger.kernel.org >> >> Link:https://protect2.fireeye.com/v1/url?k=24a746d8-45dcec51-24a6cd97- >> 74fe48600034-8e4653a49a463f3c&q=1&e=0efc824d-6463-4253-9cd7- >> ce3199dbf513&u=https%3A%2F%2Fsyzkaller.appspot.com%2Fbug%3Fid%3D50381fc738 >> 21ecae743b8cf24b4c9a04776f767c >> Reported-by:syzbot+a4087e40b9c13aad7892@syzkaller.appspotmail.com >> Fixes: 1e49a94cf707 ("exfat: add bitmap operations") >> Signed-off-by: Tadeusz Struk<tadeusz.struk@linaro.org> > Looks good. > And it seems that WARN_ON() is no longer needed.
Right. Do you want me to send a follow up patch that drops the WARN_ONs?
> Reviewed-by: Sungjong Seo<sj1557.seo@samsung.com> >
Thank you.
-- Thanks, Tadeusz
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