KASAN reports that there is a use-after-free case of bio in btrfs_map_bio. If we need to submit IOs to several disks at a time, the original bio would get cloned and mapped to the destination disk, but we really should use the original bio instead of a cloned bio to do the sanity check because cloned bios are likely to be freed by its endio.
Reported-by: Diego <[email protected]> Signed-off-by: Liu Bo <[email protected]> --- fs/btrfs/volumes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 73d56ee..ab8a66d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -6213,7 +6213,7 @@ int btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio, for (dev_nr = 0; dev_nr < total_devs; dev_nr++) { dev = bbio->stripes[dev_nr].dev; if (!dev || !dev->bdev || - (bio_op(bio) == REQ_OP_WRITE && !dev->writeable)) { + (bio_op(first_bio) == REQ_OP_WRITE && !dev->writeable)) { bbio_error(bbio, first_bio, logical); continue; } -- 2.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
