6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bragatheswaran Manickavel <bragathemanick0908@xxxxxxxxx> commit f91192cd68591c6b037da345bc9fcd5e50540358 upstream. In btrfs_ref_tree_mod(), when !parent 're' was allocated through kmalloc(). In the following code, if an error occurs, the execution will be redirected to 'out' or 'out_unlock' and the function will be exited. However, on some of the paths, 're' are not deallocated and may lead to memory leaks. For example: lookup_block_entry() for 'be' returns NULL, the out label will be invoked. During that flow ref and 'ra' are freed but not 're', which can potentially lead to a memory leak. CC: stable@xxxxxxxxxxxxxxx # 5.10+ Reported-and-tested-by: syzbot+d66de4cbf532749df35f@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=d66de4cbf532749df35f Signed-off-by: Bragatheswaran Manickavel <bragathemanick0908@xxxxxxxxx> Reviewed-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/btrfs/ref-verify.c | 2 ++ 1 file changed, 2 insertions(+) --- a/fs/btrfs/ref-verify.c +++ b/fs/btrfs/ref-verify.c @@ -791,6 +791,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_i dump_ref_action(fs_info, ra); kfree(ref); kfree(ra); + kfree(re); goto out_unlock; } else if (be->num_refs == 0) { btrfs_err(fs_info, @@ -800,6 +801,7 @@ int btrfs_ref_tree_mod(struct btrfs_fs_i dump_ref_action(fs_info, ra); kfree(ref); kfree(ra); + kfree(re); goto out_unlock; }
