diff mbox

[3.8.y.z,extended,stable] Patch "audit: use nlmsg_len() to get message payload length" has been added to staging queue

Message ID 1386371298-30370-1-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Dec. 6, 2013, 11:08 p.m. UTC 
This is a note to let you know that I have just added a patch titled

    audit: use nlmsg_len() to get message payload length

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.14.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

From 77e88477907147abf35bf89f5d2ccdffd07c0ead Mon Sep 17 00:00:00 2001
From: Mathias Krause <minipli@googlemail.com>
Date: Mon, 30 Sep 2013 22:04:25 +0200
Subject: audit: use nlmsg_len() to get message payload length

commit 4d8fe7376a12bf4524783dd95cbc00f1fece6232 upstream.

Using the nlmsg_len member of the netlink header to test if the message
is valid is wrong as it includes the size of the netlink header itself.
Thereby allowing to send short netlink messages that pass those checks.

Use nlmsg_len() instead to test for the right message length. The result
of nlmsg_len() is guaranteed to be non-negative as the netlink message
already passed the checks of nlmsg_ok().

Also switch to min_t() to please checkpatch.pl.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
[ kamal: backport to 3.8 (addtional bits from 46e959ea) ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 kernel/audit.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

--
1.8.3.2
diff mbox

Patch

diff --git a/kernel/audit.c b/kernel/audit.c
index bccbce0..5924919 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -688,7 +688,7 @@  static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 				 &status_set, sizeof(status_set));
 		break;
 	case AUDIT_SET:
-		if (nlh->nlmsg_len < sizeof(struct audit_status))
+		if (nlmsg_len(nlh) < sizeof(struct audit_status))
 			return -EINVAL;
 		status_get   = (struct audit_status *)data;
 		if (status_get->mask & AUDIT_STATUS_ENABLED) {
@@ -881,17 +881,17 @@  static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 		break;
 	}
 	case AUDIT_TTY_SET: {
-		struct audit_tty_status *s;
+		struct audit_tty_status s;
 		struct task_struct *tsk = current;

-		if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
-			return -EINVAL;
-		s = data;
-		if (s->enabled != 0 && s->enabled != 1)
+		memset(&s, 0, sizeof(s));
+		/* guard against past and future API changes */
+		memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
+		if (s.enabled != 0 && s.enabled != 1)
 			return -EINVAL;

 		spin_lock_irq(&tsk->sighand->siglock);
-		tsk->signal->audit_tty = s->enabled != 0;
+		tsk->signal->audit_tty = s.enabled != 0;
 		spin_unlock_irq(&tsk->sighand->siglock);
 		break;
 	}