blob: a97ee037247f63d878c0a648b770b2b56e51fa8e [file] [log] [blame]
From: Jeff Mahoney <jeffm@suse.com>
Date: Wed, 21 Sep 2016 08:31:29 -0400
Subject: 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>
---
fs/btrfs/ioctl.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1302,6 +1302,9 @@ static noinline int btrfs_ioctl_snap_cre
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_cre
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_cre
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_des
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);