From cba85b532e4aabdb97f44c18987d45141fd93faa Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 6 Jan 2011 11:25:00 -0800 Subject: [PATCH] netfilter: fix export secctx error handling In 1ae4de0cdf855305765592647025bde55e85e451, the secctx was exported via the /proc/net/netfilter/nf_conntrack and ctnetlink interfaces instead of the secmark. That patch introduced the use of security_secid_to_secctx() which may return a non-zero value on error. In one of my setups, I have NF_CONNTRACK_SECMARK enabled but no security modules. Thus, security_secid_to_secctx() returns a negative value that results in the breakage of the /proc and `conntrack -L' outputs. To fix this, we skip the inclusion of secctx if the aforementioned function fails. This patch also fixes the dynamic netlink message size calculation if security_secid_to_secctx() returns an error, since its logic is also wrong. This problem exists in Linux kernel >= 2.6.37. Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller --- .../nf_conntrack_l3proto_ipv4_compat.c | 2 +- net/netfilter/nf_conntrack_netlink.c | 25 +++++++++++-------- net/netfilter/nf_conntrack_standalone.c | 2 +- 3 files changed, 16 insertions(+), 13 deletions(-) diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c index 37f8adb68c7..63f60fc5d26 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c @@ -97,7 +97,7 @@ static int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) ret = security_secid_to_secctx(ct->secmark, &secctx, &len); if (ret) - return ret; + return 0; ret = seq_printf(s, "secctx=%s ", secctx); diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index b729ace1dcc..0cdba50c0d6 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -254,7 +254,7 @@ ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) ret = security_secid_to_secctx(ct->secmark, &secctx, &len); if (ret) - return ret; + return 0; ret = -1; nest_secctx = nla_nest_start(skb, CTA_SECCTX | NLA_F_NESTED); @@ -453,16 +453,22 @@ ctnetlink_counters_size(const struct nf_conn *ct) ; } -#ifdef CONFIG_NF_CONNTRACK_SECMARK -static int ctnetlink_nlmsg_secctx_size(const struct nf_conn *ct) +static inline int +ctnetlink_secctx_size(const struct nf_conn *ct) { - int len; +#ifdef CONFIG_NF_CONNTRACK_SECMARK + int len, ret; - security_secid_to_secctx(ct->secmark, NULL, &len); + ret = security_secid_to_secctx(ct->secmark, NULL, &len); + if (ret) + return 0; - return sizeof(char) * len; -} + return nla_total_size(0) /* CTA_SECCTX */ + + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */ +#else + return 0; #endif +} static inline size_t ctnetlink_nlmsg_size(const struct nf_conn *ct) @@ -479,10 +485,7 @@ ctnetlink_nlmsg_size(const struct nf_conn *ct) + nla_total_size(0) /* CTA_PROTOINFO */ + nla_total_size(0) /* CTA_HELP */ + nla_total_size(NF_CT_HELPER_NAME_LEN) /* CTA_HELP_NAME */ -#ifdef CONFIG_NF_CONNTRACK_SECMARK - + nla_total_size(0) /* CTA_SECCTX */ - + nla_total_size(ctnetlink_nlmsg_secctx_size(ct)) /* CTA_SECCTX_NAME */ -#endif + + ctnetlink_secctx_size(ct) #ifdef CONFIG_NF_NAT_NEEDED + 2 * nla_total_size(0) /* CTA_NAT_SEQ_ADJ_ORIG|REPL */ + 6 * nla_total_size(sizeof(u_int32_t)) /* CTA_NAT_SEQ_OFFSET */ diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 0fb65705b44..b4d7f0f24b2 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -118,7 +118,7 @@ static int ct_show_secctx(struct seq_file *s, const struct nf_conn *ct) ret = security_secid_to_secctx(ct->secmark, &secctx, &len); if (ret) - return ret; + return 0; ret = seq_printf(s, "secctx=%s ", secctx); -- 2.20.1