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Commit cdfb080e authored by Chris Mason's avatar Chris Mason
Browse files

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: default avatarChris Mason <clm@fb.com>
parent 1bbc621e

fs/btrfs/ctree.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

fs/btrfs/disk-io.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

fs/btrfs/extent-tree.c

+5 −0
Original line number Diff line number Diff line
@@ -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)