Received-SPF: pass (google.com: domain of linux-kernel+bounces-112232-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
From: Andrey Shumilin <shum.sdl@nppct.ru>
To: Chandan Babu R <chandan.babu@oracle.com>
Cc: Andrey Shumilin <shum.sdl@nppct.ru>,
	"Darrick J. Wong" <djwong@kernel.org>,
	Dave Chinner <dchinner@redhat.com>,
	linux-xfs@vger.kernel.org,
	linux-kernel@vger.kernel.org (open list),
	lvc-project@linuxtesting.org,
	khoroshilov@ispras.ru,
	ykarpov@ispras.ru,
	vmerzlyakov@ispras.ru,
	vefanov@ispras.ru
Subject: [PATCH 2/2] xfs_refcount: Preventing integer overflow
Date: Sat, 23 Mar 2024 09:26:03 +0300
Message-Id: <20240323062603.665572-1-shum.sdl@nppct.ru>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Multiplying variables can overflow the "overhead" variable.
To fix this, the variable type has been increased.
Next, a subtraction operation occurs with it,
but before that it is checked.

Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Andrey Shumilin <shum.sdl@nppct.ru>
---
 fs/xfs/libxfs/xfs_refcount.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_refcount.c b/fs/xfs/libxfs/xfs_refcount.c
index 511c912d515c..cbf07552eaff 100644
--- a/fs/xfs/libxfs/xfs_refcount.c
+++ b/fs/xfs/libxfs/xfs_refcount.c
@@ -1070,7 +1070,7 @@ static bool
 xfs_refcount_still_have_space(
 	struct xfs_btree_cur		*cur)
 {
-	unsigned long			overhead;
+	unsigned long long		overhead;
 
 	/*
 	 * Worst case estimate: full splits of the free space and rmap btrees
-- 
2.30.2