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authorOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>2022-01-09 10:36:43 +0100
committerJens Axboe <axboe@kernel.dk>2022-01-20 14:30:12 +0100
commit3ee859e384d453d6ac68bfd5971f630d9fa46ad3 (patch)
tree16e2d6b6407e50614f4f0c6ef9882305cd5fd27f /block
parentblock: assign bi_bdev for cloned bios in blk_rq_prep_clone (diff)
downloadlinux-3ee859e384d453d6ac68bfd5971f630d9fa46ad3.tar.xz
linux-3ee859e384d453d6ac68bfd5971f630d9fa46ad3.zip
block: Fix wrong offset in bio_truncate()
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> Reviewed-by: Ming Lei <ming.lei@redhat.com> Link: https://lore.kernel.org/r/875yqt1c9g.fsf@mail.parknet.co.jp Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/bio.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/block/bio.c b/block/bio.c
index 0d400ba2dbd1..4312a8085396 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -569,7 +569,8 @@ static void bio_truncate(struct bio *bio, unsigned new_size)
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;