ovl: check snprintf return

Miklos Szeredi · Miklos Szeredi · commit 6787341a0f15 · 2017-07-27T21:54:05.000+02:00
Signed-off-by: Miklos Szeredi &lt;mszeredi@redhat.com&gt;
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
@@ -498,6 +498,9 @@ static int ovl_set_nlink_common(struct dentry *dentry,
 	len = snprintf(buf, sizeof(buf), format,
 		       (int) (inode->i_nlink - realinode->i_nlink));
 
+	if (WARN_ON(len >= sizeof(buf)))
+		return -EIO;
+
 	return ovl_do_setxattr(ovl_dentry_upper(dentry),
 			       OVL_XATTR_NLINK, buf, len, 0);
 }

Original file line number	Diff line number	Diff line change
`@@ -498,6 +498,9 @@ static int ovl_set_nlink_common(struct dentry *dentry,`
`498`	`498`	`len = snprintf(buf, sizeof(buf), format,`
`499`	`499`	`(int) (inode->i_nlink - realinode->i_nlink));`
`500`	`500`
	`501`	`+ if (WARN_ON(len >= sizeof(buf)))`
	`502`	`+ return -EIO;`
	`503`	`+`
`501`	`504`	`return ovl_do_setxattr(ovl_dentry_upper(dentry),`
`502`	`505`	`OVL_XATTR_NLINK, buf, len, 0);`
`503`	`506`	`}`