net: Fix recursive descent in __scm_destroy().

[net-next-2.6.git] / net / core / scm.c

diff --git a/net/core/scm.c b/net/core/scm.c
index 44c4ec2c8769b1a922d69a6f0e5882bc6f58f001..ab242cc1accaae7673b76784aa5838a76d9b10c4 100644 (file)
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -24,6 +24,8 @@
 #include <linux/interrupt.h>
 #include <linux/netdevice.h>
 #include <linux/security.h>
+#include <linux/pid.h>
+#include <linux/nsproxy.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -42,7 +44,7 @@
 
 static __inline__ int scm_check_creds(struct ucred *creds)
 {
-       if ((creds->pid == current->tgid || capable(CAP_SYS_ADMIN)) &&
+       if ((creds->pid == task_tgid_vnr(current) || capable(CAP_SYS_ADMIN)) &&
            ((creds->uid == current->uid || creds->uid == current->euid ||
              creds->uid == current->suid) || capable(CAP_SETUID)) &&
            ((creds->gid == current->gid || creds->gid == current->egid ||
@@ -73,6 +75,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
                if (!fpl)
                        return -ENOMEM;
                *fplp = fpl;
+               INIT_LIST_HEAD(&fpl->list);
                fpl->count = 0;
        }
        fpp = &fpl->fp[fpl->count];
@@ -104,9 +107,25 @@ void __scm_destroy(struct scm_cookie *scm)
 
        if (fpl) {
                scm->fp = NULL;
-               for (i=fpl->count-1; i>=0; i--)
-                       fput(fpl->fp[i]);
-               kfree(fpl);
+               if (current->scm_work_list) {
+                       list_add_tail(&fpl->list, current->scm_work_list);
+               } else {
+                       LIST_HEAD(work_list);
+
+                       current->scm_work_list = &work_list;
+
+                       list_add(&fpl->list, &work_list);
+                       while (!list_empty(&work_list)) {
+                               fpl = list_first_entry(&work_list, struct scm_fp_list, list);
+
+                               list_del(&fpl->list);
+                               for (i=fpl->count-1; i>=0; i--)
+                                       fput(fpl->fp[i]);
+                               kfree(fpl);
+                       }
+
+                       current->scm_work_list = NULL;
+               }
        }
 }
 
@@ -167,7 +186,8 @@ error:
 
 int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
 {
-       struct cmsghdr __user *cm = (struct cmsghdr __user *)msg->msg_control;
+       struct cmsghdr __user *cm
+               = (__force struct cmsghdr __user *)msg->msg_control;
        struct cmsghdr cmhdr;
        int cmlen = CMSG_LEN(len);
        int err;
@@ -193,6 +213,8 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data)
        if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))
                goto out;
        cmlen = CMSG_SPACE(len);
+       if (msg->msg_controllen < cmlen)
+               cmlen = msg->msg_controllen;
        msg->msg_control += cmlen;
        msg->msg_controllen -= cmlen;
        err = 0;
@@ -202,7 +224,8 @@ out:
 
 void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
 {
-       struct cmsghdr __user *cm = (struct cmsghdr __user*)msg->msg_control;
+       struct cmsghdr __user *cm
+               = (__force struct cmsghdr __user*)msg->msg_control;
 
        int fdmax = 0;
        int fdnum = scm->fp->count;
@@ -222,7 +245,8 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
        if (fdnum < fdmax)
                fdmax = fdnum;
 
-       for (i=0, cmfptr=(int __user *)CMSG_DATA(cm); i<fdmax; i++, cmfptr++)
+       for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
+            i++, cmfptr++)
        {
                int new_fd;
                err = security_file_receive(fp[i]);
@@ -277,6 +301,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl)
 
        new_fpl = kmalloc(sizeof(*fpl), GFP_KERNEL);
        if (new_fpl) {
+               INIT_LIST_HEAD(&new_fpl->list);
                for (i=fpl->count-1; i>=0; i--)
                        get_file(fpl->fp[i]);
                memcpy(new_fpl, fpl, sizeof(*fpl));