From cdfb080e1853660952db5e5332727e59427856df Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Mon, 6 Apr 2015 18:17:00 -0700 Subject: [PATCH] Btrfs: fix use after free when close_ctree frees the orphan_rsv Near the end of close_ctree, we're calling btrfs_free_block_rsv to free up the orphan rsv. The problem is this call updates the space_info, which has already been freed. This adds a new __ function that directly calls kfree instead of trying to update the space infos. Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 1 + fs/btrfs/disk-io.c | 2 +- fs/btrfs/extent-tree.c | 5 +++++ 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 83051fae9467..10b6a75ab7e6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3470,6 +3470,7 @@ struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root, unsigned short type); void btrfs_free_block_rsv(struct btrfs_root *root, struct btrfs_block_rsv *rsv); +void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv); int btrfs_block_rsv_add(struct btrfs_root *root, struct btrfs_block_rsv *block_rsv, u64 num_bytes, enum btrfs_reserve_flush_enum flush); diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index b5e3d5f6400a..62cd3b63190d 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3766,7 +3766,7 @@ void close_ctree(struct btrfs_root *root) btrfs_free_stripe_hash_table(fs_info); - btrfs_free_block_rsv(root, root->orphan_block_rsv); + __btrfs_free_block_rsv(root->orphan_block_rsv); root->orphan_block_rsv = NULL; lock_chunks(root); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 02c2b29a0840..875ba519a131 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -4918,6 +4918,11 @@ void btrfs_free_block_rsv(struct btrfs_root *root, kfree(rsv); } +void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv) +{ + kfree(rsv); +} + int btrfs_block_rsv_add(struct btrfs_root *root, struct btrfs_block_rsv *block_rsv, u64 num_bytes, enum btrfs_reserve_flush_enum flush) -- 2.20.1