Re: [PATCH 08/16] ipvs: fix ip_vs_set_timeout debug messages
From: Simon Horman <horms@verge.net.au>
Date: 2012-10-09 01:48:36
Also in:
linux-arm-kernel, lkml, netfilter-devel
On Sat, Oct 06, 2012 at 09:54:15AM +0000, Arnd Bergmann wrote:
On Saturday 06 October 2012, Julian Anastasov wrote:quoted
On Sat, 6 Oct 2012, Arnd Bergmann wrote:quoted
quoted
Are there any CONFIG_IP_VS_PROTO_xxx options in this default config? It is a waste of memory if IPVS is compiled without any protocols.They all appear to be turned off: $ grep CONFIG_IP_VS obj-tmp/.config CONFIG_IP_VS=m CONFIG_IP_VS_DEBUG=y CONFIG_IP_VS_TAB_BITS=12 # CONFIG_IP_VS_PROTO_TCP is not set # CONFIG_IP_VS_PROTO_UDP is not set # CONFIG_IP_VS_PROTO_AH_ESP is not set # CONFIG_IP_VS_PROTO_ESP is not set # CONFIG_IP_VS_PROTO_AH is not set # CONFIG_IP_VS_PROTO_SCTP is not setSomething should be changed here, may be at least TCP/UDP, who knows.I don't try to read too much into our defconfigs. We have 140 of them on ARM, and they are mainly useful to give a reasonable build coverage, but I wouldn't expect them to be actually used on that hardware. I'll leave it up to Krzysztof to send a patch for this if he wants.quoted
quoted
--- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c@@ -2590,6 +2588,7 @@ __ip_vs_get_timeouts(struct net *net, struct ip_vs_timeout_user *u) #if defined(CONFIG_IP_VS_PROTO_TCP) || defined(CONFIG_IP_VS_PROTO_UDP) struct ip_vs_proto_data *pd; #endifThat is what we want. If you plan another submission you can add empty line before this memset and to replace the __ip_vs_get_timeouts call in ip_vs_genl_set_config with memset but they are cosmetic changes. Or may be Simon will take care about the coding style when applying the change. Acked-by: Julian Anastasov <ja@ssi.bg>I'd prefer Simon to pick up the patch. He should also decide whether he wants to add it to stable. In theory, this is a small leak of kernel stack data to user space, but as you say in practice it should not happen because it only exists for silly configurations that nobody should be using. AFAICT, removing the call to __ip_vs_get_timeouts in do_ip_vs_get_ctl would be a semantic change for the case where a user sends a IPVS_CMD_SET_CONFIG message without without the complete set of attributes inside it. The current behavior is to leave the timeouts alone, replacing the __ip_vs_get_timeouts with a memset would zero them. I left this part alone then. Arnd
Hi, sorry for being a bit slow, it was a long weekend here. This patch looks reasonable and I think it is appropriate for stable. I'll see about getting it merged accordingly.
quoted hunk ↗ jump to hunk
8<----- ipvs: initialize returned data in do_ip_vs_get_ctl As reported by a gcc warning, the do_ip_vs_get_ctl does not initalize all the members of the ip_vs_timeout_user structure it returns if at least one of the TCP or UDP protocols is disabled for ipvs. This makes sure that the data is always initialized, before it is returned as a response to IPVS_CMD_GET_CONFIG or printed as a debug message in IPVS_CMD_SET_CONFIG. Without this patch, building ARM ixp4xx_defconfig results in: net/netfilter/ipvs/ip_vs_ctl.c: In function 'ip_vs_genl_set_cmd': net/netfilter/ipvs/ip_vs_ctl.c:2238:47: warning: 't.udp_timeout' may be used uninitialized in this function [-Wuninitialized] net/netfilter/ipvs/ip_vs_ctl.c:3322:28: note: 't.udp_timeout' was declared here net/netfilter/ipvs/ip_vs_ctl.c:2238:47: warning: 't.tcp_fin_timeout' may be used uninitialized in this function [-Wuninitialized] net/netfilter/ipvs/ip_vs_ctl.c:3322:28: note: 't.tcp_fin_timeout' was declared here net/netfilter/ipvs/ip_vs_ctl.c:2238:47: warning: 't.tcp_timeout' may be used uninitialized in this function [-Wuninitialized] net/netfilter/ipvs/ip_vs_ctl.c:3322:28: note: 't.tcp_timeout' was declared here Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Julian Anastasov <ja@ssi.bg> ---diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 2770f85..c4ee437 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c@@ -2591,6 +2589,8 @@ __ip_vs_get_timeouts(struct net *net, struct ip_vs_timeout_user *u) struct ip_vs_proto_data *pd; #endif + memset(u, 0, sizeof (*u)); + #ifdef CONFIG_IP_VS_PROTO_TCP pd = ip_vs_proto_data_get(net, IPPROTO_TCP); u->tcp_timeout = pd->timeout_table[IP_VS_TCP_S_ESTABLISHED] / HZ;@@ -2768,7 +2768,6 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) { struct ip_vs_timeout_user t; - memset(&t, 0, sizeof(t)); __ip_vs_get_timeouts(net, &t); if (copy_to_user(user, &t, sizeof(t)) != 0) ret = -EFAULT;