Re: [PATCH] ipvs: Fix signed integer overflow when setsockopt timeout

["zhangxiaoxu (A)" <zhangxiaoxu5@huawei.com>]

ping.

On 1/14/2019 8:15 PM, Simon Horman wrote:
> On Thu, Jan 10, 2019 at 04:39:06PM +0800, ZhangXiaoxu wrote:
>> There is a UBSAN bug report as below:
>> UBSAN: Undefined behaviour in net/netfilter/ipvs/ip_vs_ctl.c:2227:21
>> signed integer overflow:
>> -2147483647 * 1000 cannot be represented in type 'int'
>>
>> Reproduce program:
>> 	#include <stdio.h>
>> 	#include <sys/types.h>
>> 	#include <sys/socket.h>
>>
>> 	#define IPPROTO_IP 0
>> 	#define IPPROTO_RAW 255
>>
>> 	#define IP_VS_BASE_CTL		(64+1024+64)
>> 	#define IP_VS_SO_SET_TIMEOUT	(IP_VS_BASE_CTL+10)
>>
>> 	/* The argument to IP_VS_SO_GET_TIMEOUT */
>> 	struct ipvs_timeout_t {
>> 		int tcp_timeout;
>> 		int tcp_fin_timeout;
>> 		int udp_timeout;
>> 	};
>>
>> 	int main() {
>> 		int ret = -1;
>> 		int sockfd = -1;
>> 		struct ipvs_timeout_t to;
>>
>> 		sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
>> 		if (sockfd == -1) {
>> 			printf("socket init error\n");
>> 			return -1;
>> 		}
>>
>> 		to.tcp_timeout = -2147483647;
>> 		to.tcp_fin_timeout = -2147483647;
>> 		to.udp_timeout = -2147483647;
>>
>> 		ret = setsockopt(sockfd,
>> 				 IPPROTO_IP,
>> 				 IP_VS_SO_SET_TIMEOUT,
>> 				 (char *)(&to),
>> 				 sizeof(to));
>>
>> 		printf("setsockopt return %d\n", ret);
>> 		return ret;
>> 	}
>>
>> Return -EINVAL if the timeout value is negative or max than 'INT_MAX / HZ'.
>>
>> Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
> 
> Thanks, this looks good to me.
> 
> Pablo, could you consider applying this to nf?
> 
> Acked-by: Simon Horman <horms@verge.net.au>
> 
>> ---
>>   net/netfilter/ipvs/ip_vs_ctl.c | 13 +++++++++++++
>>   1 file changed, 13 insertions(+)
>>
>> diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
>> index 432141f..444aaca 100644
>> --- a/net/netfilter/ipvs/ip_vs_ctl.c
>> +++ b/net/netfilter/ipvs/ip_vs_ctl.c
>> @@ -2221,6 +2221,19 @@ static int ip_vs_set_timeout(struct netns_ipvs *ipvs, struct ip_vs_timeout_user
>>   		  u->udp_timeout);
>>   
>>   #ifdef CONFIG_IP_VS_PROTO_TCP
>> +	if (u->tcp_timeout < 0 || u->tcp_timeout > (INT_MAX / HZ) ||
>> +	    u->tcp_fin_timeout < 0 || u->tcp_fin_timeout > (INT_MAX / HZ)) {
>> +		return -EINVAL;
>> +	}
>> +#endif
>> +
>> +#ifdef CONFIG_IP_VS_PROTO_UDP
>> +	if (u->udp_timeout < 0 || u->udp_timeout > (INT_MAX / HZ)) {
>> +		return -EINVAL;
>> +	}
>> +#endif
>> +
>> +#ifdef CONFIG_IP_VS_PROTO_TCP
>>   	if (u->tcp_timeout) {
>>   		pd = ip_vs_proto_data_get(ipvs, IPPROTO_TCP);
>>   		pd->timeout_table[IP_VS_TCP_S_ESTABLISHED]
>> -- 
>> 2.7.4
>>
> 
> .
>