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| author | Jeff Mahoney <jeffm@suse.com> | 2016-09-21 08:31:29 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-11-20 01:01:42 +0000 |
| commit | aa1e138422a6bd04a7b0cbd425919cbd834cd395 (patch) | |
| tree | e45fdd69c94c7a8eff23f96880e150acf5b2505d | |
| parent | 25a0d70d6162a76eebfbff33acd5746d99c32c4e (diff) | |
| download | lwn-aa1e138422a6bd04a7b0cbd425919cbd834cd395.tar.gz lwn-aa1e138422a6bd04a7b0cbd425919cbd834cd395.zip | |
btrfs: ensure that file descriptor used with subvol ioctls is a dir
commit 325c50e3cebb9208009083e841550f98a863bfa0 upstream.
If the subvol/snapshot create/destroy ioctls are passed a regular file
with execute permissions set, we'll eventually Oops while trying to do
inode->i_op->lookup via lookup_one_len.
This patch ensures that the file descriptor refers to a directory.
Fixes: cb8e70901d (Btrfs: Fix subvolume creation locking rules)
Fixes: 76dda93c6a (Btrfs: add snapshot/subvolume destroy ioctl)
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
[bwh: Backported to 3.2:
- Open-code file_inode()
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | fs/btrfs/ioctl.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index eb6a0e6f6ecd..360072f42afe 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1302,6 +1302,9 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file, int namelen; int ret = 0; + if (!S_ISDIR(file->f_dentry->d_inode->i_mode)) + return -ENOTDIR; + if (root->fs_info->sb->s_flags & MS_RDONLY) return -EROFS; @@ -1350,6 +1353,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, struct btrfs_ioctl_vol_args *vol_args; int ret; + if (!S_ISDIR(file->f_dentry->d_inode->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); @@ -1372,6 +1378,9 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, u64 *ptr = NULL; bool readonly = false; + if (!S_ISDIR(file->f_dentry->d_inode->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); @@ -1848,6 +1857,9 @@ static noinline int btrfs_ioctl_snap_destroy(struct file *file, int ret; int err = 0; + if (!S_ISDIR(dir->i_mode)) + return -ENOTDIR; + vol_args = memdup_user(arg, sizeof(*vol_args)); if (IS_ERR(vol_args)) return PTR_ERR(vol_args); |