lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[AF_UNIX]: Kernel memory leak fix for af_unix datagram getpeersec patch

Browse Source 
From: Catherine Zhang <cxzhang@watson.ibm.com>

This patch implements a cleaner fix for the memory leak problem of the
original unix datagram getpeersec patch.  Instead of creating a
security context each time a unix datagram is sent, we only create the
security context when the receiver requests it.

This new design requires modification of the current
unix_getsecpeer_dgram LSM hook and addition of two new hooks, namely,
secid_to_secctx and release_secctx.  The former retrieves the security
context and the latter releases it.  A hook is required for releasing
the security context because it is up to the security module to decide
how that's done.  In the case of Selinux, it's a simple kfree
operation.

Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Catherine Zhang
2006-08-02 14:12:06 -07:00
committed by David S. Miller
parent 2b7e24b66d
commit dc49c1f94e
7 changed files with 110 additions and 44 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
security/selinux/hooks.c
View File

@ -3524,25 +3524,21 @@ out:
return err;
}
static int selinux_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata, u32 *seclen)
static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
{
u32 peer_secid = SECSID_NULL;
int err = 0;
u32 peer_sid;
if (skb->sk->sk_family == PF_UNIX)
selinux_get_inode_sid(SOCK_INODE(skb->sk->sk_socket),
&peer_sid);
else
peer_sid = selinux_socket_getpeer_dgram(skb);
if (sock && (sock->sk->sk_family == PF_UNIX))
selinux_get_inode_sid(SOCK_INODE(sock), &peer_secid);
else if (skb)
peer_secid = selinux_socket_getpeer_dgram(skb);
if (peer_sid == SECSID_NULL)
return -EINVAL;
if (peer_secid == SECSID_NULL)
err = -EINVAL;
*secid = peer_secid;
err = security_sid_to_context(peer_sid, secdata, seclen);
if (err)
return err;
return 0;
return err;
}
static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
@ -4407,6 +4403,17 @@ static int selinux_setprocattr(struct task_struct *p,
return size;
}
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
return security_sid_to_context(secid, secdata, seclen);
}
static void selinux_release_secctx(char *secdata, u32 seclen)
{
if (secdata)
kfree(secdata);
}
#ifdef CONFIG_KEYS
static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
@ -4587,6 +4594,9 @@ static struct security_operations selinux_ops = {
.getprocattr = selinux_getprocattr,
.setprocattr = selinux_setprocattr,
.secid_to_secctx = selinux_secid_to_secctx,
.release_secctx = selinux_release_secctx,
.unix_stream_connect = selinux_socket_unix_stream_connect,
.unix_may_send = selinux_socket_unix_may_send,