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| author | Catherine Zhang <cxzhang@watson.ibm.com> | 2006-08-03 01:12:06 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2006-08-03 01:12:06 +0400 |
| commit | dc49c1f94e3469d94b952e8f5160dd4ccd791d79 (patch) | |
| tree | e47b1974c262a03dbabf0a148325d9089817e78e /include/net/scm.h | |
| parent | 2b7e24b66d31d677d76b49918e711eb360c978b6 (diff) | |
| download | linux-dc49c1f94e3469d94b952e8f5160dd4ccd791d79.tar.xz | |
[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 'include/net/scm.h')
| -rw-r--r-- | include/net/scm.h | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/include/net/scm.h b/include/net/scm.h index 02daa097cdcd..5637d5e22d5f 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -3,6 +3,7 @@ #include <linux/limits.h> #include <linux/net.h> +#include <linux/security.h> /* Well, we should have at least one descriptor open * to accept passed FDs 8) @@ -20,8 +21,7 @@ struct scm_cookie struct ucred creds; /* Skb credentials */ struct scm_fp_list *fp; /* Passed files */ #ifdef CONFIG_SECURITY_NETWORK - char *secdata; /* Security context */ - u32 seclen; /* Security length */ + u32 secid; /* Passed security ID */ #endif unsigned long seq; /* Connection seqno */ }; @@ -32,6 +32,16 @@ extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie extern void __scm_destroy(struct scm_cookie *scm); extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl); +#ifdef CONFIG_SECURITY_NETWORK +static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) +{ + security_socket_getpeersec_dgram(sock, NULL, &scm->secid); +} +#else +static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm) +{ } +#endif /* CONFIG_SECURITY_NETWORK */ + static __inline__ void scm_destroy(struct scm_cookie *scm) { if (scm && scm->fp) @@ -47,6 +57,7 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, scm->creds.pid = p->tgid; scm->fp = NULL; scm->seq = 0; + unix_get_peersec_dgram(sock, scm); if (msg->msg_controllen <= 0) return 0; return __scm_send(sock, msg, scm); @@ -55,8 +66,18 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg, #ifdef CONFIG_SECURITY_NETWORK static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) { - if (test_bit(SOCK_PASSSEC, &sock->flags) && scm->secdata != NULL) - put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, scm->seclen, scm->secdata); + char *secdata; + u32 seclen; + int err; + + if (test_bit(SOCK_PASSSEC, &sock->flags)) { + err = security_secid_to_secctx(scm->secid, &secdata, &seclen); + + if (!err) { + put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata); + security_release_secctx(secdata, seclen); + } + } } #else static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm) |