From cfaf2d034360166e569a4929dd83ae9698bed856 Mon Sep 17 00:00:00 2001
From: Brian Foster <bfoster@redhat.com>
Date: Mon, 24 Jul 2017 08:33:25 -0700
Subject: [PATCH] xfs: fix quotacheck dquot id overflow infinite loop
Git-commit: cfaf2d034360166e569a4929dd83ae9698bed856
Patch-mainline: v4.13-rc3
References: bsc#1121621
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>
Acked-by: Anthony Iliopoulos <ailiopoulos@suse.com>
---
fs/xfs/xfs_qm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 6ce948c436d5..15751dc2a27d 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -111,6 +111,9 @@ xfs_qm_dquot_walk(
skipped = 0;
break;
}
+ /* we're done if id overflows back to zero */
+ if (!next_index)
+ break;
}
if (skipped) {
--
2.16.4