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| author | Filipe Manana <fdmanana@suse.com> | 2018-11-14 14:35:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 21:32:06 +0300 |
| commit | 78a2890fcda1c48ce44c06313984310e1c3b96d7 (patch) | |
| tree | 5c645c15ccdc717912b8b49fa54712a71a4ebdaa /fs/btrfs | |
| parent | aaf249e36785c49043a6072a555bad32b5fba1b1 (diff) | |
| download | linux-78a2890fcda1c48ce44c06313984310e1c3b96d7.tar.xz | |
Btrfs: ensure path name is null terminated at btrfs_control_ioctl
commit f505754fd6599230371cb01b9332754ddc104be1 upstream.
We were using the path name received from user space without checking that
it is null terminated. While btrfs-progs is well behaved and does proper
validation and null termination, someone could call the ioctl and pass
a non-null terminated patch, leading to buffer overrun problems in the
kernel. The ioctl is protected by CAP_SYS_ADMIN.
So just set the last byte of the path to a null character, similar to what
we do in other ioctls (add/remove/resize device, snapshot creation, etc).
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/btrfs')
| -rw-r--r-- | fs/btrfs/super.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 6601c9aa5e35..8ad145820ea8 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2235,6 +2235,7 @@ static long btrfs_control_ioctl(struct file *file, unsigned int cmd, vol = memdup_user((void __user *)arg, sizeof(*vol)); if (IS_ERR(vol)) return PTR_ERR(vol); + vol->name[BTRFS_PATH_NAME_MAX] = '\0'; switch (cmd) { case BTRFS_IOC_SCAN_DEV: |