[PATCH 6.4 764/800] btrfs: fix extent buffer leak after tree mod log failure at split_node()

Greg Kroah-Hartman
2023-07-16T20:28:33Z

From: Filipe Manana <fdmanana@suse.com>

commit ede600e497b1461d06d22a7d17703d9096868bc3 upstream.

At split_node(), if we fail to log the tree mod log copy operation, we
return without unlocking the split extent buffer we just allocated and
without decrementing the reference we own on it. Fix this by unlocking
it and decrementing the ref count before returning.

Fixes: 5de865eebb83 ("Btrfs: fix tree mod logging")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/ctree.c | 2 ++
1 file changed, 2 insertions(+)

--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2982,6 +2982,8 @@ static noinline int split_node(struct bt

ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid);
if (ret) {
+ btrfs_tree_unlock(split);
+ free_extent_buffer(split);
btrfs_abort_transaction(trans, ret);
return ret;
}