This is a note to let you know that I've just added the patch titled fs/ufs: avoid potential u32 multiplication overflow to the 4.9-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-ufs-avoid-potential-u32-multiplication-overflow.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit cecf48823315553b210e6ef43c140a367a89d8b0 Author: Colin Ian King <colin.king@xxxxxxxxxxxxx> Date: Tue Aug 11 18:35:53 2020 -0700 fs/ufs: avoid potential u32 multiplication overflow [ Upstream commit 88b2e9b06381551b707d980627ad0591191f7a2d ] The 64 bit ino is being compared to the product of two u32 values, however, the multiplication is being performed using a 32 bit multiply so there is a potential of an overflow. To be fully safe, cast uspi->s_ncg to a u64 to ensure a 64 bit multiplication occurs to avoid any chance of overflow. Fixes: f3e2a520f5fb ("ufs: NFS support") Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Evgeniy Dushistov <dushistov@xxxxxxx> Cc: Alexey Dobriyan <adobriyan@xxxxxxxxx> Link: http://lkml.kernel.org/r/20200715170355.1081713-1-colin.king@xxxxxxxxxxxxx Addresses-Coverity: ("Unintentional integer overflow") Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/ufs/super.c b/fs/ufs/super.c index 351162ff1bfd2..e320d824ee4d9 100644 --- a/fs/ufs/super.c +++ b/fs/ufs/super.c @@ -99,7 +99,7 @@ static struct inode *ufs_nfs_get_inode(struct super_block *sb, u64 ino, u32 gene struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi; struct inode *inode; - if (ino < UFS_ROOTINO || ino > uspi->s_ncg * uspi->s_ipg) + if (ino < UFS_ROOTINO || ino > (u64)uspi->s_ncg * uspi->s_ipg) return ERR_PTR(-ESTALE); inode = ufs_iget(sb, ino);