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[4.9,046/134] fs/jfs: fix potential integer overflow on shift of a int

Message ID 20210301161015.848258857@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman March 1, 2021, 4:12 p.m. UTC 
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(-)
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Patch

diff --git a/fs/jfs/jfs_dmap.c b/fs/jfs/jfs_dmap.c
index 2d514c7affc2a..9ff510a489cb1 100644
--- a/fs/jfs/jfs_dmap.c
+++ b/fs/jfs/jfs_dmap.c
@@ -1669,7 +1669,7 @@  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");