Ming Lei <ming.lei@xxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxxxxxxx >> Signed-off-by: OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx> >> --- >> 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@xxxxxxxxxx> ping? -- OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
