1 files changed, 37 insertions, 9 deletions

diff --git a/net/core/scm.c b/net/core/scm.c
index b7ba91b074b..bbe45445080 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -26,6 +26,7 @@
 #include <linux/security.h>
 #include <linux/pid.h>
 #include <linux/nsproxy.h>
+#include <linux/slab.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -78,10 +79,11 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
 			return -ENOMEM;
 		*fplp = fpl;
 		fpl->count = 0;
+		fpl->max = SCM_MAX_FD;
 	}
 	fpp = &fpl->fp[fpl->count];
 
-	if (fpl->count + num > SCM_MAX_FD)
+	if (fpl->count + num > fpl->max)
 		return -EINVAL;
 
 	/*
@@ -129,6 +131,7 @@ void __scm_destroy(struct scm_cookie *scm)
 		}
 	}
 }
+EXPORT_SYMBOL(__scm_destroy);
 
 int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
 {
@@ -156,6 +159,8 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
 		switch (cmsg->cmsg_type)
 		{
 		case SCM_RIGHTS:
+			if (!sock->ops || sock->ops->family != PF_UNIX)
+				goto error;
 			err=scm_fp_copy(cmsg, &p->fp);
 			if (err<0)
 				goto error;
@@ -167,6 +172,30 @@ int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *p)
 			err = scm_check_creds(&p->creds);
 			if (err)
 				goto error;
+
+			if (pid_vnr(p->pid) != p->creds.pid) {
+				struct pid *pid;
+				err = -ESRCH;
+				pid = find_get_pid(p->creds.pid);
+				if (!pid)
+					goto error;
+				put_pid(p->pid);
+				p->pid = pid;
+			}
+
+			if ((p->cred->euid != p->creds.uid) ||
+				(p->cred->egid != p->creds.gid)) {
+				struct cred *cred;
+				err = -ENOMEM;
+				cred = prepare_creds();
+				if (!cred)
+					goto error;
+
+				cred->uid = cred->euid = p->creds.uid;
+				cred->gid = cred->egid = p->creds.uid;
+				put_cred(p->cred);
+				p->cred = cred;
+			}
 			break;
 		default:
 			goto error;
@@ -184,6 +213,7 @@ error:
 	scm_destroy(p);
 	return err;
 }
+EXPORT_SYMBOL(__scm_send);
 
 int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
 {
@@ -222,6 +252,7 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
 out:
 	return err;
 }
+EXPORT_SYMBOL(put_cmsg);
 
 void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 {
@@ -291,6 +322,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 	 */
 	__scm_destroy(scm);
 }
+EXPORT_SYMBOL(scm_detach_fds);
 
 struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
 {
@@ -300,17 +332,13 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
 	if (!fpl)
 		return NULL;
 
-	new_fpl = kmalloc(sizeof(*fpl), GFP_KERNEL);
+	new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),
+			  GFP_KERNEL);
 	if (new_fpl) {
-		for (i=fpl->count-1; i>=0; i--)
+		for (i = 0; i < fpl->count; i++)
 			get_file(fpl->fp[i]);
-		memcpy(new_fpl, fpl, sizeof(*fpl));
+		new_fpl->max = new_fpl->count;
 	}
 	return new_fpl;
 }
-
-EXPORT_SYMBOL(__scm_destroy);
-EXPORT_SYMBOL(__scm_send);
-EXPORT_SYMBOL(put_cmsg);
-EXPORT_SYMBOL(scm_detach_fds);
 EXPORT_SYMBOL(scm_fp_dup);