ANDROID: xt_quota2: remove trailing junk which might have a digit in it

Make sure string only contains the characters specified by userspace.

Fix cherry-picked from xtables-extensions project

Signed-off-by: Sam Liddicott <sam@liddicott.com>
Mot-CRs-fixed: (CR)
CVE-Fixed: CVE-2021-0961

Bug: 196046570
Test: passed netd test suites
Fixes: 10cda83af99d ("ANDROID: netfilter: xt_quota2: adding the
original quota2 from xtables-addons")
Signed-off-by: Todd Kjos <tkjos@google.com>
(cherry picked from https://git.code.sf.net/p/xtables-addons/xtables-addons
bc2bcc383c70b293bd816c29523a952ca8736fb5)
Change-Id: I965448564906e5fbf0fe6d6414f44d9e257ea195
Signed-off-by: Gajjala Chakradhar <gajjalac@motorola.com>
Reviewed-on: https://gerrit.mot.com/2123622
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
(cherry picked from commit 625eb505d4c123adcc699c2a73aeec1390adf03c)

diff --git a/net/netfilter/xt_quota2.c b/net/netfilter/xt_quota2.c
index 24b774263aa6aa9a800e0f3c46c381e3ddcc165c..75afbe20d0cb222947b7fad7f9c8c5d1ed8cb708 100644 (file)
--- a/net/netfilter/xt_quota2.c
+++ b/net/netfilter/xt_quota2.c
@@ -162,6 +162,8 @@ static ssize_t quota_proc_write(struct file *file, const char __user *input,
        if (copy_from_user(buf, input, size) != 0)
                return -EFAULT;
        buf[sizeof(buf)-1] = '\0';
+       if (size < sizeof(buf))
+               buf[size] = '\0';
 
        spin_lock_bh(&e->lock);
        e->quota = simple_strtoull(buf, NULL, 0);