From: Liu Bo Date: Mon, 10 Apr 2017 19:36:26 +0000 (-0700) Subject: Btrfs: fix potential use-after-free for cloned bio X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a967efb30b3afa3d858edd6a17f544f9e9e46eea;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git Btrfs: fix potential use-after-free for cloned bio 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 Signed-off-by: Liu Bo Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 7c8c7bbee197..7c7e0c99360f 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; }