[PATCH 2/2] xfs: fix integer overflow in busy extent sort comparator

[Yuto Ohnuki]

xfs_extent_busy_ag_cmp() subtracts two uint32_t values (group
numbers and block numbers) and returns the result as s32. When
the difference exceeds INT_MAX, the result overflows and the sort
order is corrupted.

Use cmp_int() instead, as was done in commit 362c49098086 ("xfs:
fix integer overflow in bmap intent sort comparator").

Fixes: 4a137e09151e ("xfs: keep a reference to the pag for busy extents")
Signed-off-by: Yuto Ohnuki <ytohnuki@xxxxxxxxxx>
---
 fs/xfs/xfs_extent_busy.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_extent_busy.c b/fs/xfs/xfs_extent_busy.c
index 3efdca3d675b..41cf0605ec22 100644
--- a/fs/xfs/xfs_extent_busy.c
+++ b/fs/xfs/xfs_extent_busy.c
@@ -690,9 +690,9 @@ xfs_extent_busy_ag_cmp(
 		container_of(l2, struct xfs_extent_busy, list);
 	s32 diff;
 
-	diff = b1->group->xg_gno - b2->group->xg_gno;
+	diff = cmp_int(b1->group->xg_gno, b2->group->xg_gno);
 	if (!diff)
-		diff = b1->bno - b2->bno;
+		diff = cmp_int(b1->bno, b2->bno);
 	return diff;
 }
 
-- 
2.50.1




Amazon Web Services EMEA SARL, 38 avenue John F. Kennedy, L-1855 Luxembourg, R.C.S. Luxembourg B186284

Amazon Web Services EMEA SARL, Irish Branch, One Burlington Plaza, Burlington Road, Dublin 4, Ireland, branch registration number 908705