4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Brian Foster <[email protected]> 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 <[email protected]> Reviewed-by: Darrick J. Wong <[email protected]> Signed-off-by: Darrick J. Wong <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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) {
