xfs: fix quotacheck dquot id overflow infinite loop

If a dquot has an id of U32_MAX, the next lookup index increment
overflows the uint32_t back to 0. This starts the lookup sequence
over from the beginning, repeats indefinitely and results in a
livelock.

Update xfs_qm_dquot_walk() to explicitly check for the lookup
overflow and exit the loop.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Brian Foster 2017-07-24 08:33:25 -07:00 committed by Darrick J. Wong
parent 10479e2dea
commit cfaf2d0343

View File

@ -111,6 +111,9 @@ restart:
skipped = 0;
break;
}
/* we're done if id overflows back to zero */
if (!next_index)
break;
}
if (skipped) {