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[107/165] fs/ufs: avoid potential u32 multiplication overflow

Message ID 20200812013553.jHLcfo7PH%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [001/165] percpu: return number of released bytes from pcpu_free_area() | expand

Commit Message

Andrew Morton Aug. 12, 2020, 1:35 a.m. UTC 
From: Colin Ian King <colin.king@canonical.com>
Subject: fs/ufs: avoid potential u32 multiplication overflow

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.

Addresses-Coverity: ("Unintentional integer overflow")
Link: http://lkml.kernel.org/r/20200715170355.1081713-1-colin.king@canonical.com
Fixes: f3e2a520f5fb ("ufs: NFS support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 fs/ufs/super.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

--- a/fs/ufs/super.c~fs-ufs-avoid-potential-u32-multiplication-overflow
+++ a/fs/ufs/super.c
@@ -101,7 +101,7 @@  static struct inode *ufs_nfs_get_inode(s
 	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);