diff mbox

[14/47] xfs: fix quotacheck dquot id overflow infinite loop

Message ID 20170917210712.10804-15-hch@lst.de (mailing list archive)
State Accepted
Headers show

Commit Message

Christoph Hellwig Sept. 17, 2017, 9:06 p.m. UTC 
From: Brian Foster <bfoster@redhat.com>

commit cfaf2d034360166e569a4929dd83ae9698bed856 upstream.

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>
---
 fs/xfs/xfs_qm.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox

Patch

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 8068867a8183..1fdd3face2d9 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) {