From: Eric Biggers ebiggers@google.com

UBIFS's implementation of FS_IOC_SETFLAGS fails to preserve existing inode flags that aren't settable by FS_IOC_SETFLAGS, namely the encrypt flag. This causes the encrypt flag to be unexpectedly cleared.

Fix it by preserving existing unsettable flags, like ext4 and f2fs do.

Test case with kvm-xfstests shell:

FSTYP=ubifs KEYCTL_PROG=keyctl . fs/ubifs/config . ~/xfstests/common/encrypt dev=$(__blkdev_to_ubi_volume /dev/vdc) ubiupdatevol -t $dev mount $dev /mnt -t ubifs k=$(_generate_session_encryption_key) mkdir /mnt/edir xfs_io -c "set_encpolicy $k" /mnt/edir echo contents > /mnt/edir/file chattr +i /mnt/edir/file chattr -i /mnt/edir/file

With the bug, the following errors occur on the last command:

[ 18.081559] fscrypt (ubifs, inode 67): Inconsistent encryption context (parent directory: 65) chattr: Operation not permitted while reading flags on /mnt/edir/file

Fixes: d475a507457b ("ubifs: Add skeleton for fscrypto") Cc: stable@vger.kernel.org # v4.10+ Signed-off-by: Eric Biggers ebiggers@google.com --- fs/ubifs/ioctl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c index 5dc5abca11c70..eeb1be2598881 100644 --- a/fs/ubifs/ioctl.c +++ b/fs/ubifs/ioctl.c @@ -113,7 +113,8 @@ static int setflags(struct inode *inode, int flags) if (err) goto out_unlock;

- ui->flags = ioctl2ubifs(flags); + ui->flags &= ~ioctl2ubifs(UBIFS_SUPPORTED_IOCTL_FLAGS); + ui->flags |= ioctl2ubifs(flags); ubifs_set_inode_flags(inode); inode->i_ctime = current_time(inode); release = ui->dirty;