87 lines
2.6 KiB
Diff
87 lines
2.6 KiB
Diff
From b8baf1c21a214c1b836eef390c9d6e153293fef9 Mon Sep 17 00:00:00 2001
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From: Dan Carpenter <dan.carpenter@oracle.com>
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Date: Thu, 3 Oct 2013 00:27:20 +0300
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Subject: net: heap overflow in __audit_sockaddr()
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From: Dan Carpenter <dan.carpenter@oracle.com>
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[ Upstream commit 1661bf364ae9c506bc8795fef70d1532931be1e8 ]
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We need to cap ->msg_namelen or it leads to a buffer overflow when we
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to the memcpy() in __audit_sockaddr(). It requires CAP_AUDIT_CONTROL to
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exploit this bug.
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The call tree is:
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___sys_recvmsg()
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move_addr_to_user()
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audit_sockaddr()
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__audit_sockaddr()
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Reported-by: Jüri Aedla <juri.aedla@gmail.com>
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Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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net/compat.c | 2 ++
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net/socket.c | 24 ++++++++++++++++++++----
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2 files changed, 22 insertions(+), 4 deletions(-)
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--- a/net/compat.c
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+++ b/net/compat.c
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@@ -71,6 +71,8 @@ int get_compat_msghdr(struct msghdr *kms
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__get_user(kmsg->msg_controllen, &umsg->msg_controllen) ||
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__get_user(kmsg->msg_flags, &umsg->msg_flags))
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return -EFAULT;
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+ if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
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+ return -EINVAL;
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kmsg->msg_name = compat_ptr(tmp1);
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kmsg->msg_iov = compat_ptr(tmp2);
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kmsg->msg_control = compat_ptr(tmp3);
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--- a/net/socket.c
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+++ b/net/socket.c
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@@ -1973,6 +1973,16 @@ struct used_address {
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unsigned int name_len;
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};
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+static int copy_msghdr_from_user(struct msghdr *kmsg,
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+ struct msghdr __user *umsg)
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+{
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+ if (copy_from_user(kmsg, umsg, sizeof(struct msghdr)))
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+ return -EFAULT;
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+ if (kmsg->msg_namelen > sizeof(struct sockaddr_storage))
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+ return -EINVAL;
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+ return 0;
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+}
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+
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static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
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struct msghdr *msg_sys, unsigned int flags,
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struct used_address *used_address)
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@@ -1991,8 +2001,11 @@ static int ___sys_sendmsg(struct socket
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if (MSG_CMSG_COMPAT & flags) {
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if (get_compat_msghdr(msg_sys, msg_compat))
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return -EFAULT;
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- } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
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- return -EFAULT;
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+ } else {
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+ err = copy_msghdr_from_user(msg_sys, msg);
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+ if (err)
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+ return err;
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+ }
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if (msg_sys->msg_iovlen > UIO_FASTIOV) {
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err = -EMSGSIZE;
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@@ -2200,8 +2213,11 @@ static int ___sys_recvmsg(struct socket
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if (MSG_CMSG_COMPAT & flags) {
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if (get_compat_msghdr(msg_sys, msg_compat))
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return -EFAULT;
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- } else if (copy_from_user(msg_sys, msg, sizeof(struct msghdr)))
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- return -EFAULT;
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+ } else {
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+ err = copy_msghdr_from_user(msg_sys, msg);
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+ if (err)
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+ return err;
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+ }
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if (msg_sys->msg_iovlen > UIO_FASTIOV) {
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err = -EMSGSIZE;
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