[PATCH] collect sid of those who send signals to auditd

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/include/linux/audit.h b/include/linux/audit.h
index 1a221b6..1057e90 100644 (file)
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -278,6 +278,7 @@ struct audit_rule {         /* for AUDIT_LIST, AUDIT_ADD, and AUDIT_DEL */
 struct audit_sig_info {
        uid_t           uid;
        pid_t           pid;
+       char            ctx[0];
 };
 
 struct audit_buffer;
@@ -328,7 +329,6 @@ extern int audit_bprm(struct linux_binprm *bprm);
 extern int audit_socketcall(int nargs, unsigned long *args);
 extern int audit_sockaddr(int len, void *addr);
 extern int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt);
-extern void audit_signal_info(int sig, struct task_struct *t);
 extern int audit_set_macxattr(const char *name);
 #else
 #define audit_alloc(t) ({ 0; })
@@ -349,7 +349,6 @@ extern int audit_set_macxattr(const char *name);
 #define audit_socketcall(n,a) ({ 0; })
 #define audit_sockaddr(len, addr) ({ 0; })
 #define audit_avc_path(dentry, mnt) ({ 0; })
-#define audit_signal_info(s,t) do { ; } while (0)
 #define audit_set_macxattr(n) do { ; } while (0)
 #endif
 

diff --git a/kernel/audit.c b/kernel/audit.c
index d09f131..bb20922 100644 (file)
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -89,6 +89,7 @@ static int    audit_backlog_wait_overflow = 0;
 /* The identity of the user shutting down the audit system. */
 uid_t          audit_sig_uid = -1;
 pid_t          audit_sig_pid = -1;
+u32            audit_sig_sid = 0;
 
 /* Records can be lost in several ways:
    0) [suppressed in audit_alloc]
@@ -479,7 +480,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        struct audit_buffer     *ab;
        u16                     msg_type = nlh->nlmsg_type;
        uid_t                   loginuid; /* loginuid of sender */
-       struct audit_sig_info   sig_data;
+       struct audit_sig_info   *sig_data;
+       char                    *ctx;
+       u32                     len;
 
        err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type);
        if (err)
@@ -531,12 +534,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                if (status_get->mask & AUDIT_STATUS_PID) {
                        int old   = audit_pid;
                        if (sid) {
-                               char *ctx = NULL;
-                               u32 len;
-                               int rc;
-                               if ((rc = selinux_ctxid_to_string(
+                               if ((err = selinux_ctxid_to_string(
                                                sid, &ctx, &len)))
-                                       return rc;
+                                       return err;
                                else
                                        audit_log(NULL, GFP_KERNEL,
                                                AUDIT_CONFIG_CHANGE,
@@ -572,8 +572,6 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                                 "user pid=%d uid=%u auid=%u",
                                                 pid, uid, loginuid);
                                if (sid) {
-                                       char *ctx = NULL;
-                                       u32 len;
                                        if (selinux_ctxid_to_string(
                                                        sid, &ctx, &len)) {
                                                audit_log_format(ab, 
@@ -612,10 +610,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                           loginuid, sid);
                break;
        case AUDIT_SIGNAL_INFO:
-               sig_data.uid = audit_sig_uid;
-               sig_data.pid = audit_sig_pid;
+               err = selinux_ctxid_to_string(audit_sig_sid, &ctx, &len);
+               if (err)
+                       return err;
+               sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
+               if (!sig_data) {
+                       kfree(ctx);
+                       return -ENOMEM;
+               }
+               sig_data->uid = audit_sig_uid;
+               sig_data->pid = audit_sig_pid;
+               memcpy(sig_data->ctx, ctx, len);
+               kfree(ctx);
                audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, 
-                               0, 0, &sig_data, sizeof(sig_data));
+                               0, 0, sig_data, sizeof(*sig_data) + len);
+               kfree(sig_data);
                break;
        default:
                err = -EINVAL;

diff --git a/kernel/audit.h b/kernel/audit.h
index 8948fc1..52cb1e3 100644 (file)
--- a/kernel/audit.h
+++ b/kernel/audit.h
@@ -101,3 +101,14 @@ struct audit_netlink_list {
 int audit_send_list(void *);
 
 extern int selinux_audit_rule_update(void);
+
+#ifdef CONFIG_AUDITSYSCALL
+extern void __audit_signal_info(int sig, struct task_struct *t);
+static inline void audit_signal_info(int sig, struct task_struct *t)
+{
+       if (unlikely(audit_pid && t->tgid == audit_pid))
+               __audit_signal_info(sig, t);
+}
+#else
+#define audit_signal_info(s,t)
+#endif

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 114f921..4ca913d 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1376,19 +1376,20 @@ int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
  * If the audit subsystem is being terminated, record the task (pid)
  * and uid that is doing that.
  */
-void audit_signal_info(int sig, struct task_struct *t)
+void __audit_signal_info(int sig, struct task_struct *t)
 {
        extern pid_t audit_sig_pid;
        extern uid_t audit_sig_uid;
-
-       if (unlikely(audit_pid && t->tgid == audit_pid)) {
-               if (sig == SIGTERM || sig == SIGHUP) {
-                       struct audit_context *ctx = current->audit_context;
-                       audit_sig_pid = current->pid;
-                       if (ctx)
-                               audit_sig_uid = ctx->loginuid;
-                       else
-                               audit_sig_uid = current->uid;
-               }
+       extern u32 audit_sig_sid;
+
+       if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) {
+               struct task_struct *tsk = current;
+               struct audit_context *ctx = tsk->audit_context;
+               audit_sig_pid = tsk->pid;
+               if (ctx)
+                       audit_sig_uid = ctx->loginuid;
+               else
+                       audit_sig_uid = tsk->uid;
+               selinux_get_task_sid(tsk, &audit_sig_sid);
        }
 }

diff --git a/kernel/signal.c b/kernel/signal.c
index e5f8aea..1b3c921 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -23,12 +23,12 @@
 #include <linux/syscalls.h>
 #include <linux/ptrace.h>
 #include <linux/signal.h>
-#include <linux/audit.h>
 #include <linux/capability.h>
 #include <asm/param.h>
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/siginfo.h>
+#include "audit.h"     /* audit_signal_info() */
 
 /*
  * SLAB caches for signal bits.