Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 44/78] xfs: fix quotacheck dquot id overflow infinite loop | Date | Mon, 18 Sep 2017 11:11:53 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- fs/xfs/xfs_qm.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -111,6 +111,9 @@ restart: skipped = 0; break; } + /* we're done if id overflows back to zero */ + if (!next_index) + break; } if (skipped) {
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