From a378abbb8e394f30e97b243a018f9135b39abc96 Mon Sep 17 00:00:00 2001 From: Xiyu Yang Date: Mon, 20 Apr 2020 13:39:39 +0800 Subject: [PATCH] btrfs: fix transaction leak in btrfs_recover_relocation commit 1402d17dfd9657be0da8458b2079d03c2d61c86a upstream. btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins a btrfs_trans_handle object into transactions and returns a reference of it with increased refcount to "trans". When btrfs_recover_relocation() returns, "trans" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of btrfs_recover_relocation(). When read_fs_root() failed, the refcnt increased by btrfs_join_transaction() is not decreased, causing a refcnt leak. Fix this issue by calling btrfs_end_transaction() on this error path when read_fs_root() failed. Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/relocation.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 32a09ed5..e890f09 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -4605,6 +4605,7 @@ int btrfs_recover_relocation(struct btrfs_root *root) if (IS_ERR(fs_root)) { err = PTR_ERR(fs_root); list_add_tail(&reloc_root->root_list, &reloc_roots); + btrfs_end_transaction(trans); goto out_unset; } -- 2.7.4