diff options
| author | David Sterba <dsterba@suse.cz> | 2016-05-04 11:32:00 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-07 18:18:55 -0700 |
| commit | e5788f9679c122730e1f9978aa8413516dca7b17 (patch) | |
| tree | 35edd58904f6d681ef96f4b006e1ff37e4a8022f | |
| parent | 686d38c651290aa6f1ede263ac2b2542a5a62791 (diff) | |
btrfs: add write protection to SET_FEATURES ioctl
commit 7ab19625a911f7568ec85302e3aa7a64186006c8 upstream.
Perform the want_write check if we get far enough to do any writes.
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/btrfs/ioctl.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index ea21e588a839..14e291422ab1 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -5397,9 +5397,15 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg) if (ret) return ret; + ret = mnt_want_write_file(file); + if (ret) + return ret; + trans = btrfs_start_transaction(root, 0); - if (IS_ERR(trans)) - return PTR_ERR(trans); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_drop_write; + } spin_lock(&root->fs_info->super_lock); newflags = btrfs_super_compat_flags(super_block); @@ -5418,7 +5424,11 @@ static int btrfs_ioctl_set_features(struct file *file, void __user *arg) btrfs_set_super_incompat_flags(super_block, newflags); spin_unlock(&root->fs_info->super_lock); - return btrfs_commit_transaction(trans, root); + ret = btrfs_commit_transaction(trans, root); +out_drop_write: + mnt_drop_write_file(file); + + return ret; } long btrfs_ioctl(struct file *file, unsigned int |