btrfs: check unsupported filters in balance arguments

We don't verify that all the balance filter arguments supplemented by
the flags are actually known to the kernel. Thus we let it silently pass
and do nothing.

At the moment this means only the 'limit' filter, but we're going to add
a few more soon so it's better to have that fixed. Also in older stable
kernels so that it works with newer userspace tools.

Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

2 files changed, 13 insertions, 0 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4df0f2bd9af7..7375cf2e6bbf 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4691,6 +4691,11 @@ locked:
                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
         }
 
+        if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
+                ret = -EINVAL;
+                goto out_bargs;
+        }
+
 do_balance:
         /*
          * Ownership of bctl and mutually_exclusive_operation_running
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 99c208f6718d..b8e64ea984f1 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -381,6 +381,14 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_VRANGE       (1ULL << 4)
 #define BTRFS_BALANCE_ARGS_LIMIT        (1ULL << 5)
 
+#define BTRFS_BALANCE_ARGS_MASK                 \
+        (BTRFS_BALANCE_ARGS_PROFILES |          \
+         BTRFS_BALANCE_ARGS_USAGE |             \
+         BTRFS_BALANCE_ARGS_DEVID |             \
+         BTRFS_BALANCE_ARGS_DRANGE |            \
+         BTRFS_BALANCE_ARGS_VRANGE |            \
+         BTRFS_BALANCE_ARGS_LIMIT)
+
 /*
  * Profile changing flags.  When SOFT is set we won't relocate chunk if
  * it already has the target profile (even though it may be