From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 4/6] netfilter: x_tables: fix pointer leaks to userspace
Date: Thu, 1 Feb 2018 19:02:15 +0100 [thread overview]
Message-ID: <20180201180217.24356-5-pablo@netfilter.org> (raw)
In-Reply-To: <20180201180217.24356-1-pablo@netfilter.org>
From: Dmitry Vyukov <dvyukov@google.com>
Several netfilter matches and targets put kernel pointers into
info objects, but don't set usersize in descriptors.
This leads to kernel pointer leaks if a match/target is set
and then read back to userspace.
Properly set usersize for these matches/targets.
Found with manual code inspection.
Fixes: ec2318904965 ("xtables: extend matches and targets with .usersize")
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/xt_IDLETIMER.c | 1 +
net/netfilter/xt_LED.c | 1 +
net/netfilter/xt_limit.c | 3 +--
net/netfilter/xt_nfacct.c | 1 +
net/netfilter/xt_statistic.c | 1 +
5 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/net/netfilter/xt_IDLETIMER.c b/net/netfilter/xt_IDLETIMER.c
index ee3421ad108d..6c2482b709b1 100644
--- a/net/netfilter/xt_IDLETIMER.c
+++ b/net/netfilter/xt_IDLETIMER.c
@@ -252,6 +252,7 @@ static struct xt_target idletimer_tg __read_mostly = {
.family = NFPROTO_UNSPEC,
.target = idletimer_tg_target,
.targetsize = sizeof(struct idletimer_tg_info),
+ .usersize = offsetof(struct idletimer_tg_info, timer),
.checkentry = idletimer_tg_checkentry,
.destroy = idletimer_tg_destroy,
.me = THIS_MODULE,
diff --git a/net/netfilter/xt_LED.c b/net/netfilter/xt_LED.c
index 0971634e5444..1dcad893df78 100644
--- a/net/netfilter/xt_LED.c
+++ b/net/netfilter/xt_LED.c
@@ -198,6 +198,7 @@ static struct xt_target led_tg_reg __read_mostly = {
.family = NFPROTO_UNSPEC,
.target = led_tg,
.targetsize = sizeof(struct xt_led_info),
+ .usersize = offsetof(struct xt_led_info, internal_data),
.checkentry = led_tg_check,
.destroy = led_tg_destroy,
.me = THIS_MODULE,
diff --git a/net/netfilter/xt_limit.c b/net/netfilter/xt_limit.c
index d27b5f1ea619..61403b77361c 100644
--- a/net/netfilter/xt_limit.c
+++ b/net/netfilter/xt_limit.c
@@ -193,9 +193,8 @@ static struct xt_match limit_mt_reg __read_mostly = {
.compatsize = sizeof(struct compat_xt_rateinfo),
.compat_from_user = limit_mt_compat_from_user,
.compat_to_user = limit_mt_compat_to_user,
-#else
- .usersize = offsetof(struct xt_rateinfo, prev),
#endif
+ .usersize = offsetof(struct xt_rateinfo, prev),
.me = THIS_MODULE,
};
diff --git a/net/netfilter/xt_nfacct.c b/net/netfilter/xt_nfacct.c
index cc0518fe598e..6f92d25590a8 100644
--- a/net/netfilter/xt_nfacct.c
+++ b/net/netfilter/xt_nfacct.c
@@ -62,6 +62,7 @@ static struct xt_match nfacct_mt_reg __read_mostly = {
.match = nfacct_mt,
.destroy = nfacct_mt_destroy,
.matchsize = sizeof(struct xt_nfacct_match_info),
+ .usersize = offsetof(struct xt_nfacct_match_info, nfacct),
.me = THIS_MODULE,
};
diff --git a/net/netfilter/xt_statistic.c b/net/netfilter/xt_statistic.c
index 11de55e7a868..8710fdba2ae2 100644
--- a/net/netfilter/xt_statistic.c
+++ b/net/netfilter/xt_statistic.c
@@ -84,6 +84,7 @@ static struct xt_match xt_statistic_mt_reg __read_mostly = {
.checkentry = statistic_mt_check,
.destroy = statistic_mt_destroy,
.matchsize = sizeof(struct xt_statistic_info),
+ .usersize = offsetof(struct xt_statistic_info, master),
.me = THIS_MODULE,
};
--
2.11.0
next prev parent reply other threads:[~2018-02-01 18:02 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-01 18:02 [PATCH 0/6] Netfilter fixes for net Pablo Neira Ayuso
2018-02-01 18:02 ` [PATCH 1/6] netfilter: x_tables: fix int overflow in xt_alloc_table_info() Pablo Neira Ayuso
2018-02-01 18:02 ` [PATCH 2/6] netfilter: x_tables: avoid out-of-bounds reads in xt_request_find_{match|target} Pablo Neira Ayuso
2018-02-01 18:02 ` [PATCH 3/6] netfilter: ipset: Fix wraparound in hash:*net* types Pablo Neira Ayuso
2018-02-01 18:02 ` Pablo Neira Ayuso [this message]
2018-02-01 18:02 ` [PATCH 5/6] netfilter: ipt_CLUSTERIP: fix out-of-bounds accesses in clusterip_tg_check() Pablo Neira Ayuso
2018-02-01 18:02 ` [PATCH 6/6] netfilter: on sockopt() acquire sock lock only in the required scope Pablo Neira Ayuso
2018-02-01 19:45 ` [PATCH 0/6] Netfilter fixes for net David Miller
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