This is a note to let you know that I've just added the patch titled btrfs: fix transaction leak in btrfs_recover_relocation to the 5.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: btrfs-fix-transaction-leak-in-btrfs_recover_relocation.patch and it can be found in the queue-5.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 1402d17dfd9657be0da8458b2079d03c2d61c86a Mon Sep 17 00:00:00 2001 From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Date: Mon, 20 Apr 2020 13:39:39 +0800 Subject: btrfs: fix transaction leak in btrfs_recover_relocation From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx # 4.4+ Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx> Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/relocation.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -4614,6 +4614,7 @@ int btrfs_recover_relocation(struct btrf 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; } Patches currently in stable-queue which might be from xiyuyang19@xxxxxxxxxxxx are queue-5.6/btrfs-fix-transaction-leak-in-btrfs_recover_relocation.patch queue-5.6/btrfs-fix-block-group-leak-when-removing-fails.patch