[PATCH nf] netfilter: x_tables: Update remaining dereference to RCU

[PATCH nf] netfilter: x_tables: Update remaining dereference to RCU

[Subash Abhinov Kasiviswanathan]

This fixes the dereference to fetch the RCU pointer when holding
the appropriate xtables lock.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: cc00bcaa5899 ("netfilter: x_tables: Switch synchronization to RCU")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
---
 net/ipv4/netfilter/arp_tables.c | 2 +-
 net/ipv4/netfilter/ip_tables.c  | 2 +-
 net/ipv6/netfilter/ip6_tables.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 563b62b..c576a63 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1379,7 +1379,7 @@ static int compat_get_entries(struct net *net,
 	xt_compat_lock(NFPROTO_ARP);
 	t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
 	if (!IS_ERR(t)) {
-		const struct xt_table_info *private = t->private;
+		const struct xt_table_info *private = xt_table_get_private_protected(t);
 		struct xt_table_info info;
 
 		ret = compat_table_info(private, &info);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 6e2851f..e8f6f9d 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -1589,7 +1589,7 @@ compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr,
 	xt_compat_lock(AF_INET);
 	t = xt_find_table_lock(net, AF_INET, get.name);
 	if (!IS_ERR(t)) {
-		const struct xt_table_info *private = t->private;
+		const struct xt_table_info *private = xt_table_get_private_protected(t);
 		struct xt_table_info info;
 		ret = compat_table_info(private, &info);
 		if (!ret && get.size == info.size)
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index c4f532f..0d453fa 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1598,7 +1598,7 @@ compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr,
 	xt_compat_lock(AF_INET6);
 	t = xt_find_table_lock(net, AF_INET6, get.name);
 	if (!IS_ERR(t)) {
-		const struct xt_table_info *private = t->private;
+		const struct xt_table_info *private = xt_table_get_private_protected(t);
 		struct xt_table_info info;
 		ret = compat_table_info(private, &info);
 		if (!ret && get.size == info.size)
-- 
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a Linux Foundation Collaborative Project

Re: [PATCH nf] netfilter: x_tables: Update remaining dereference to RCU

[Florian Westphal]

Subash Abhinov Kasiviswanathan <subashab@codeaurora.org> wrote:
> This fixes the dereference to fetch the RCU pointer when holding
> the appropriate xtables lock.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Fixes: cc00bcaa5899 ("netfilter: x_tables: Switch synchronization to RCU")
> Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>

Reviewed-by: Florian Westphal <fw@strlen.de>

Re: [PATCH nf] netfilter: x_tables: Update remaining dereference to RCU

[Pablo Neira Ayuso]

On Wed, Dec 16, 2020 at 09:38:02PM -0700, Subash Abhinov Kasiviswanathan wrote:
> This fixes the dereference to fetch the RCU pointer when holding
> the appropriate xtables lock.

Applied, thanks.