* [PATCH] block: Fix wrong offset in bio_truncate()
[not found] <000000000000880fca05d4fc73b0@google.com>
@ 2022-01-09 9:36 ` OGAWA Hirofumi
2022-01-10 8:00 ` Ming Lei
2022-01-20 13:30 ` Jens Axboe
0 siblings, 2 replies; 4+ messages in thread
From: OGAWA Hirofumi @ 2022-01-09 9:36 UTC (permalink / raw)
To: linux-block; +Cc: Jens Axboe, glider, linux-kernel, syzkaller-bugs, syzbot
bio_truncate() clears the buffer outside of last block of bdev, however
current bio_truncate() is using the wrong offset of page. So it can
return the uninitialized data.
This happened when both of truncated/corrupted FS and userspace (via
bdev) are trying to read the last of bdev.
Reported-by: syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---
block/bio.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c
index a6fb6a0..25f1ed2 100644
--- a/block/bio.c 2021-11-01 09:19:05.999472589 +0900
+++ b/block/bio.c 2022-01-09 17:40:09.010438012 +0900
@@ -567,7 +567,8 @@ void bio_truncate(struct bio *bio, unsig
offset = new_size - done;
else
offset = 0;
- zero_user(bv.bv_page, offset, bv.bv_len - offset);
+ zero_user(bv.bv_page, bv.bv_offset + offset,
+ bv.bv_len - offset);
truncated = true;
}
done += bv.bv_len;
_
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] block: Fix wrong offset in bio_truncate()
2022-01-09 9:36 ` [PATCH] block: Fix wrong offset in bio_truncate() OGAWA Hirofumi
@ 2022-01-10 8:00 ` Ming Lei
2022-01-20 4:43 ` OGAWA Hirofumi
2022-01-20 13:30 ` Jens Axboe
1 sibling, 1 reply; 4+ messages in thread
From: Ming Lei @ 2022-01-10 8:00 UTC (permalink / raw)
To: OGAWA Hirofumi
Cc: linux-block, Jens Axboe, glider, linux-kernel, syzkaller-bugs,
syzbot
On Sun, Jan 09, 2022 at 06:36:43PM +0900, OGAWA Hirofumi wrote:
> bio_truncate() clears the buffer outside of last block of bdev, however
> current bio_truncate() is using the wrong offset of page. So it can
> return the uninitialized data.
>
> This happened when both of truncated/corrupted FS and userspace (via
> bdev) are trying to read the last of bdev.
>
> Reported-by: syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com
> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
> ---
> block/bio.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/block/bio.c b/block/bio.c
> index a6fb6a0..25f1ed2 100644
> --- a/block/bio.c 2021-11-01 09:19:05.999472589 +0900
> +++ b/block/bio.c 2022-01-09 17:40:09.010438012 +0900
> @@ -567,7 +567,8 @@ void bio_truncate(struct bio *bio, unsig
> offset = new_size - done;
> else
> offset = 0;
> - zero_user(bv.bv_page, offset, bv.bv_len - offset);
> + zero_user(bv.bv_page, bv.bv_offset + offset,
> + bv.bv_len - offset);
Looks correct:
Reviewed-by: Ming Lei <ming.lei@redhat.com>
--
Ming
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] block: Fix wrong offset in bio_truncate()
2022-01-10 8:00 ` Ming Lei
@ 2022-01-20 4:43 ` OGAWA Hirofumi
0 siblings, 0 replies; 4+ messages in thread
From: OGAWA Hirofumi @ 2022-01-20 4:43 UTC (permalink / raw)
To: Ming Lei
Cc: linux-block, Jens Axboe, glider, linux-kernel, syzkaller-bugs,
syzbot
Ming Lei <ming.lei@redhat.com> writes:
> On Sun, Jan 09, 2022 at 06:36:43PM +0900, OGAWA Hirofumi wrote:
>> bio_truncate() clears the buffer outside of last block of bdev, however
>> current bio_truncate() is using the wrong offset of page. So it can
>> return the uninitialized data.
>>
>> This happened when both of truncated/corrupted FS and userspace (via
>> bdev) are trying to read the last of bdev.
>>
>> Reported-by: syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com
>> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
>> ---
>> block/bio.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/block/bio.c b/block/bio.c
>> index a6fb6a0..25f1ed2 100644
>> --- a/block/bio.c 2021-11-01 09:19:05.999472589 +0900
>> +++ b/block/bio.c 2022-01-09 17:40:09.010438012 +0900
>> @@ -567,7 +567,8 @@ void bio_truncate(struct bio *bio, unsig
>> offset = new_size - done;
>> else
>> offset = 0;
>> - zero_user(bv.bv_page, offset, bv.bv_len - offset);
>> + zero_user(bv.bv_page, bv.bv_offset + offset,
>> + bv.bv_len - offset);
>
> Looks correct:
>
> Reviewed-by: Ming Lei <ming.lei@redhat.com>
ping?
--
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] block: Fix wrong offset in bio_truncate()
2022-01-09 9:36 ` [PATCH] block: Fix wrong offset in bio_truncate() OGAWA Hirofumi
2022-01-10 8:00 ` Ming Lei
@ 2022-01-20 13:30 ` Jens Axboe
1 sibling, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2022-01-20 13:30 UTC (permalink / raw)
To: OGAWA Hirofumi, linux-block; +Cc: syzbot, glider, linux-kernel, syzkaller-bugs
On Sun, 09 Jan 2022 18:36:43 +0900, OGAWA Hirofumi wrote:
> bio_truncate() clears the buffer outside of last block of bdev, however
> current bio_truncate() is using the wrong offset of page. So it can
> return the uninitialized data.
>
> This happened when both of truncated/corrupted FS and userspace (via
> bdev) are trying to read the last of bdev.
>
> [...]
Applied, thanks!
[1/1] block: Fix wrong offset in bio_truncate()
commit: 3ee859e384d453d6ac68bfd5971f630d9fa46ad3
Best regards,
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
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2022-01-09 9:36 ` [PATCH] block: Fix wrong offset in bio_truncate() OGAWA Hirofumi
2022-01-10 8:00 ` Ming Lei
2022-01-20 4:43 ` OGAWA Hirofumi
2022-01-20 13:30 ` Jens Axboe
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