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	net: heap overflow in __audit_sockaddr()
We need to cap ->msg_namelen or it leads to a buffer overflow when we
to the memcpy() in __audit_sockaddr().  It requires CAP_AUDIT_CONTROL to
exploit this bug.
The call tree is:
___sys_recvmsg()
  move_addr_to_user()
    audit_sockaddr()
      __audit_sockaddr()
Reported-by: Jüri Aedla <juri.aedla@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
			
			
This commit is contained in:
		
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						1661bf364a
					
				
					 2 changed files with 22 additions and 4 deletions
				
			
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			@ -71,6 +71,8 @@ int get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg)
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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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		|||
							
								
								
									
										24
									
								
								net/socket.c
									
									
									
									
									
								
							
							
						
						
									
										24
									
								
								net/socket.c
									
									
									
									
									
								
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			@ -1964,6 +1964,16 @@ 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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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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			@ -1982,8 +1992,11 @@ static int ___sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
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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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			@ -2191,8 +2204,11 @@ static int ___sys_recvmsg(struct socket *sock, struct msghdr __user *msg,
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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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