diff options
| author | Mark Fasheh <mfasheh@suse.com> | 2008-07-24 12:20:14 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 11:04:05 -0400 |
| commit | 5516e5957f4b99b19fffffa53bf9fbe7cc793249 (patch) | |
| tree | d5d0b0d3850fc37093300920a672b3b051c86a82 /fs/btrfs | |
| parent | 9652480bf48500885a30754b4a5c436b5b34456d (diff) | |
Btrfs: Null terminate strings passed in from userspace
The 'char name[BTRFS_PATH_NAME_MAX]' member of struct btrfs_ioctl_vol_args
is passed directly to strlen() after being copied from user. I haven't
verified this, but in theory a userspace program could pass in an
unterminated string and cause a kernel crash as strlen walks off the end of
the array.
This patch terminates the ->name string in all btrfs ioctl functions which
currently use a 'struct btrfs_ioctl_vol_args'. Since the string is now
properly terminated, it's length will never be longer than
BTRFS_PATH_NAME_MAX so that error check has been removed.
By the way, it might be better overall to just have the ioctl pass an
unterminated string + length structure but I didn't bother with that since
it'd change the kernel/user interface.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/ioctl.c | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 7d40778a90e..5e627746c4e 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -310,11 +310,9 @@ static int btrfs_ioctl_resize(struct btrfs_root *root, void __user *arg) ret = -EFAULT; goto out; } + + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; namelen = strlen(vol_args->name); - if (namelen > BTRFS_VOL_NAME_MAX) { - ret = -EINVAL; - goto out; - } mutex_lock(&root->fs_info->volume_mutex); sizestr = vol_args->name; @@ -412,11 +410,8 @@ static noinline int btrfs_ioctl_snap_create(struct btrfs_root *root, goto out; } + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; namelen = strlen(vol_args->name); - if (namelen > BTRFS_VOL_NAME_MAX) { - ret = -EINVAL; - goto out; - } if (strchr(vol_args->name, '/')) { ret = -EINVAL; goto out; @@ -487,6 +482,7 @@ long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg) ret = -EFAULT; goto out; } + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; ret = btrfs_init_new_device(root, vol_args->name); out: @@ -508,6 +504,7 @@ long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg) ret = -EFAULT; goto out; } + vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; ret = btrfs_rm_device(root, vol_args->name); out: |