This is a note to let you know that I've just added the patch titled fs/jfs: fix potential integer overflow on shift of a int to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fs-jfs-fix-potential-integer-overflow-on-shift-of-a-.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2f4a140806e6fa24c470ef9cbd04cac494c88dee Author: Colin Ian King <colin.king@xxxxxxxxxxxxx> Date: Thu Feb 11 13:01:08 2021 +0000 fs/jfs: fix potential integer overflow on shift of a int [ 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@xxxxxxxxxxxxx> Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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");