summaryrefslogtreecommitdiffstats
path: root/net/compat.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/compat.c')
-rw-r--r--net/compat.c55
1 files changed, 25 insertions, 30 deletions
diff --git a/net/compat.c b/net/compat.c
index 434838bef5f8..77f3a0e98fd0 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -281,39 +281,31 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat
return 0;
}
-void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
+static int scm_max_fds_compat(struct msghdr *msg)
{
- struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control;
- int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
- int fdnum = scm->fp->count;
- struct file **fp = scm->fp->fp;
- int __user *cmfptr;
- int err = 0, i;
+ if (msg->msg_controllen <= sizeof(struct compat_cmsghdr))
+ return 0;
+ return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int);
+}
- if (fdnum < fdmax)
- fdmax = fdnum;
+void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm)
+{
+ struct compat_cmsghdr __user *cm =
+ (struct compat_cmsghdr __user *)msg->msg_control;
+ unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0;
+ int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count);
+ int __user *cmsg_data = CMSG_USER_DATA(cm);
+ int err = 0, i;
- for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) {
- int new_fd;
- err = security_file_receive(fp[i]);
- if (err)
- break;
- err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & kmsg->msg_flags
- ? O_CLOEXEC : 0);
+ for (i = 0; i < fdmax; i++) {
+ err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags);
if (err < 0)
break;
- new_fd = err;
- err = put_user(new_fd, cmfptr);
- if (err) {
- put_unused_fd(new_fd);
- break;
- }
- /* Bump the usage count and install the file. */
- fd_install(new_fd, get_file(fp[i]));
}
if (i > 0) {
int cmlen = CMSG_COMPAT_LEN(i * sizeof(int));
+
err = put_user(SOL_SOCKET, &cm->cmsg_level);
if (!err)
err = put_user(SCM_RIGHTS, &cm->cmsg_type);
@@ -321,16 +313,19 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
err = put_user(cmlen, &cm->cmsg_len);
if (!err) {
cmlen = CMSG_COMPAT_SPACE(i * sizeof(int));
- kmsg->msg_control += cmlen;
- kmsg->msg_controllen -= cmlen;
+ if (msg->msg_controllen < cmlen)
+ cmlen = msg->msg_controllen;
+ msg->msg_control += cmlen;
+ msg->msg_controllen -= cmlen;
}
}
- if (i < fdnum)
- kmsg->msg_flags |= MSG_CTRUNC;
+
+ if (i < scm->fp->count || (scm->fp->count && fdmax <= 0))
+ msg->msg_flags |= MSG_CTRUNC;
/*
- * All of the files that fit in the message have had their
- * usage counts incremented, so we just free the list.
+ * All of the files that fit in the message have had their usage counts
+ * incremented, so we just free the list.
*/
__scm_destroy(scm);
}