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 4.4-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-ufs-avoid-potential-u32-multiplication-overflow.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2663441081806f11595dc7edad06b1ea50885601
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 10f364490833e..be68b48de1cc6 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);
