| Message ID | ce6f019b-e851-eef0-17aa-b98e3a563de4@sandeen.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Fri, Dec 16, 2016 at 06:13:53PM -0600, Eric Sandeen wrote: > The GETNEXTQUOTA interface in the kernel had a bug > (at least in xfs) where if we pass in UINT_MAX as the > ID, it incremented, warpped, and returned 0 for the next > id. This would cause userspace to start querying > again at zero, and an xfs_quota "report" command would > loop forever. This occurred if a quota ID near > UINT max existed, and later offsets within the block > wrapped the xfs_dqid_t. > > This will also be fixed in the kernel, but we should also > catch this in userspace, and stop the loop if it happens. > > Signed-off-by: Eric Sandeen <sandeen@redhat.com> Looks fine, Reviewed-by: Christoph Hellwig <hch@lst.de> -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/quota/report.c b/quota/report.c index 604f50d..bcf4a15 100644 --- a/quota/report.c +++ b/quota/report.c @@ -101,6 +101,10 @@ dump_file( if (oid) *oid = d.d_id; + /* Did kernelspace wrap? */ + if (*oid < id) + return 0; + if (!d.d_blk_softlimit && !d.d_blk_hardlimit && !d.d_ino_softlimit && !d.d_ino_hardlimit && !d.d_rtb_softlimit && !d.d_rtb_hardlimit) @@ -360,6 +360,10 @@ report_mount( if (oid) *oid = d.d_id; + /* Did kernelspace wrap? */ + if (*oid < id) + return 0; + if (flags & TERSE_FLAG) { count = 0; if ((form & XFS_BLOCK_QUOTA) && d.d_bcount)
The GETNEXTQUOTA interface in the kernel had a bug (at least in xfs) where if we pass in UINT_MAX as the ID, it incremented, warpped, and returned 0 for the next id. This would cause userspace to start querying again at zero, and an xfs_quota "report" command would loop forever. This occurred if a quota ID near UINT max existed, and later offsets within the block wrapped the xfs_dqid_t. This will also be fixed in the kernel, but we should also catch this in userspace, and stop the loop if it happens. Signed-off-by: Eric Sandeen <sandeen@redhat.com> --- -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html