xfs: check dquot resource timers

For each dquot resource, ensure either (a) the resource usage is over
the soft limit and there is a nonzero timer; or (b) usage is at or under
the soft limit and the timer is unset.  (a) is redundant with the dquot
buffer verifier, but (b) isn't checked anywhere.

Found by fuzzing xfs/426 and noticing that diskdq.btimer = add didn't
trip any kind of warning for having a timer set even with no limits.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Darrick J. Wong 2023-12-15 10:03:44 -08:00
parent 7d1f0e167a
commit 774b5c0a51

View File

@ -117,6 +117,23 @@ xchk_quota_item_bmap(
return 0;
}
/* Complain if a quota timer is incorrectly set. */
static inline void
xchk_quota_item_timer(
struct xfs_scrub *sc,
xfs_fileoff_t offset,
const struct xfs_dquot_res *res)
{
if ((res->softlimit && res->count > res->softlimit) ||
(res->hardlimit && res->count > res->hardlimit)) {
if (!res->timer)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
} else {
if (res->timer)
xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
}
}
/* Scrub the fields in an individual quota item. */
STATIC int
xchk_quota_item(
@ -224,6 +241,10 @@ xchk_quota_item(
dq->q_rtb.count > dq->q_rtb.hardlimit)
xchk_fblock_set_warning(sc, XFS_DATA_FORK, offset);
xchk_quota_item_timer(sc, offset, &dq->q_blk);
xchk_quota_item_timer(sc, offset, &dq->q_ino);
xchk_quota_item_timer(sc, offset, &dq->q_rtb);
out:
if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
return -ECANCELED;