From dc49c1f94e3469d94b952e8f5160dd4ccd791d79 Mon Sep 17 00:00:00 2001 From: Catherine Zhang Date: Wed, 2 Aug 2006 14:12:06 -0700 Subject: [AF_UNIX]: Kernel memory leak fix for af_unix datagram getpeersec patch From: Catherine Zhang 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 Signed-off-by: David S. Miller --- include/linux/security.h | 41 +++++++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index f75303831d0..aa5b8043dc3 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1109,6 +1109,16 @@ struct swap_info_struct; * @name contains the name of the security module being unstacked. * @ops contains a pointer to the struct security_operations of the module to unstack. * + * @secid_to_secctx: + * Convert secid to security context. + * @secid contains the security ID. + * @secdata contains the pointer that stores the converted security context. + * + * @release_secctx: + * Release the security context. + * @secdata contains the security context. + * @seclen contains the length of the security context. + * * This is the main security structure. */ struct security_operations { @@ -1289,6 +1299,8 @@ struct security_operations { int (*getprocattr)(struct task_struct *p, char *name, void *value, size_t size); int (*setprocattr)(struct task_struct *p, char *name, void *value, size_t size); + int (*secid_to_secctx)(u32 secid, char **secdata, u32 *seclen); + void (*release_secctx)(char *secdata, u32 seclen); #ifdef CONFIG_SECURITY_NETWORK int (*unix_stream_connect) (struct socket * sock, @@ -1317,7 +1329,7 @@ struct security_operations { int (*socket_shutdown) (struct socket * sock, int how); int (*socket_sock_rcv_skb) (struct sock * sk, struct sk_buff * skb); int (*socket_getpeersec_stream) (struct socket *sock, char __user *optval, int __user *optlen, unsigned len); - int (*socket_getpeersec_dgram) (struct sk_buff *skb, char **secdata, u32 *seclen); + int (*socket_getpeersec_dgram) (struct socket *sock, struct sk_buff *skb, u32 *secid); int (*sk_alloc_security) (struct sock *sk, int family, gfp_t priority); void (*sk_free_security) (struct sock *sk); unsigned int (*sk_getsid) (struct sock *sk, struct flowi *fl, u8 dir); @@ -2059,6 +2071,16 @@ static inline int security_netlink_recv(struct sk_buff * skb, int cap) return security_ops->netlink_recv(skb, cap); } +static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + return security_ops->secid_to_secctx(secid, secdata, seclen); +} + +static inline void security_release_secctx(char *secdata, u32 seclen) +{ + return security_ops->release_secctx(secdata, seclen); +} + /* prototypes */ extern int security_init (void); extern int register_security (struct security_operations *ops); @@ -2725,6 +2747,15 @@ static inline void securityfs_remove(struct dentry *dentry) { } +static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + return -EOPNOTSUPP; +} + +static inline void security_release_secctx(char *secdata, u32 seclen) +{ + return -EOPNOTSUPP; +} #endif /* CONFIG_SECURITY */ #ifdef CONFIG_SECURITY_NETWORK @@ -2840,10 +2871,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __ return security_ops->socket_getpeersec_stream(sock, optval, optlen, len); } -static inline int security_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata, - u32 *seclen) +static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) { - return security_ops->socket_getpeersec_dgram(skb, secdata, seclen); + return security_ops->socket_getpeersec_dgram(sock, skb, secid); } static inline int security_sk_alloc(struct sock *sk, int family, gfp_t priority) @@ -2968,8 +2998,7 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __ return -ENOPROTOOPT; } -static inline int security_socket_getpeersec_dgram(struct sk_buff *skb, char **secdata, - u32 *seclen) +static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) { return -ENOPROTOOPT; } -- cgit