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: d475a50745 ("ubifs: Add skeleton for fscrypto")
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2b57067a77