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> -- Ming
