Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Colin Ian King <colin.king@canonical.com>,
        Dave Kleikamp <dave.kleikamp@oracle.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 121/340] fs/jfs: fix potential integer overflow on shift of a int
Date:   Mon,  1 Mar 2021 17:11:05 +0100
Message-Id: <20210301161054.290891384@linuxfoundation.org>
In-Reply-To: <20210301161048.294656001@linuxfoundation.org>
References: <20210301161048.294656001@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit 4208c398aae4c2290864ba15c3dab7111f32bec1 ]

The left shift of int 32 bit integer constant 1 is evaluated using 32 bit
arithmetic and then assigned to a signed 64 bit integer. In the case where
l2nb is 32 or more this can lead to an overflow.  Avoid this by shifting
the value 1LL instead.

Addresses-Coverity: ("Uninitentional integer overflow")
Fixes: b40c2e665cd5 ("fs/jfs: TRIM support for JFS Filesystem")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/jfs/jfs_dmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index caade185e568d..6fe82ce8663ef 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -1656,7 +1656,7 @@ s64 dbDiscardAG(struct inode *ip, int agno, s64 minlen)
 		} else if (rc == -ENOSPC) {
 			/* search for next smaller log2 block */
 			l2nb = BLKSTOL2(nblocks) - 1;
-			nblocks = 1 << l2nb;
+			nblocks = 1LL << l2nb;
 		} else {
 			/* Trim any already allocated blocks */
 			jfs_error(bmp->db_ipbmap->i_sb, "-EIO\n");
-- 
2.27.0