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| author | Catherine Zhang <cxzhang@watson.ibm.com> | 2006-08-02 23:12:06 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2006-08-02 23:12:06 +0200 |
| commit | dc49c1f94e3469d94b952e8f5160dd4ccd791d79 (patch) | |
| tree | e47b1974c262a03dbabf0a148325d9089817e78e /security/selinux | |
| parent | [NET]: skb_queue_lock_key() is no longer used. (diff) | |
| download | linux-dc49c1f94e3469d94b952e8f5160dd4ccd791d79.tar.xz linux-dc49c1f94e3469d94b952e8f5160dd4ccd791d79.zip | |
[AF_UNIX]: Kernel memory leak fix for af_unix datagram getpeersec patch
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>
Diffstat (limited to 'security/selinux')
| -rw-r--r-- | security/selinux/hooks.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a91c961ba38b..5d1b8c733199 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -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 (peer_sid == SECSID_NULL) - return -EINVAL; + 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); - err = security_sid_to_context(peer_sid, secdata, seclen); - if (err) - return err; + if (peer_secid == SECSID_NULL) + err = -EINVAL; + *secid = peer_secid; - 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, |