This is a note to let you know that I've just added the patch titled xfs: fix quotacheck dquot id overflow infinite loop to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: xfs-fix-quotacheck-dquot-id-overflow-infinite-loop.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From hch@xxxxxx Mon Sep 18 10:09:04 2017 From: Christoph Hellwig <hch@xxxxxx> Date: Sun, 17 Sep 2017 14:06:39 -0700 Subject: xfs: fix quotacheck dquot id overflow infinite loop To: stable@xxxxxxxxxxxxxxx Cc: linux-xfs@xxxxxxxxxxxxxxx, Brian Foster <bfoster@xxxxxxxxxx>, "Darrick J . Wong" <darrick.wong@xxxxxxxxxx> Message-ID: <20170917210712.10804-15-hch@xxxxxx> From: Brian Foster <bfoster@xxxxxxxxxx> 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@xxxxxxxxxx> Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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) { Patches currently in stable-queue which might be from hch@xxxxxx are queue-4.9/xfs-fix-inobt-inode-allocation-search-optimization.patch queue-4.9/xfs-try-to-avoid-blowing-out-the-transaction-reservation-when-bunmaping-a-shared-extent.patch queue-4.9/xfs-free-cowblocks-and-retry-on-buffered-write-enospc.patch queue-4.9/xfs-set-firstfsb-to-nullfsblock-before-feeding-it-to-_bmapi_write.patch queue-4.9/xfs-fix-quotacheck-dquot-id-overflow-infinite-loop.patch queue-4.9/xfs-remove-bli-from-ail-before-release-on-transaction-abort.patch queue-4.9/xfs-check-_btree_check_block-value.patch queue-4.9/xfs-don-t-allow-bmap-on-rt-files.patch queue-4.9/xfs-free-uncommitted-transactions-during-log-recovery.patch queue-4.9/xfs-don-t-crash-on-unexpected-holes-in-dir-attr-btrees.patch queue-4.9/xfs-fix-spurious-spin_is_locked-assert-failures-on-non-smp-kernels.patch queue-4.9/xfs-fix-per-inode-dax-flag-inheritance.patch queue-4.9/xfs-fix-multi-ag-deadlock-in-xfs_bunmapi.patch queue-4.9/xfs-release-bli-from-transaction-properly-on-fs-shutdown.patch queue-4.9/xfs-check-_alloc_read_agf-buffer-pointer-before-using.patch