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authorXin Long <lucien.xin@gmail.com>2017-08-18 11:01:36 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-30 10:21:42 +0200
commit3e00bf91fefced104ba91721674efe4502cb416a (patch)
treeb5c65a0b185a5e5d23b29fcb9064294f7eadfc8c /net/sched
parentf3f5bf2755c75d43930aab28f1affd0602e6fd27 (diff)
net: sched: fix NULL pointer dereference when action calls some targets
[ Upstream commit 4f8a881acc9d1adaf1e552349a0b1df28933a04c ] As we know in some target's checkentry it may dereference par.entryinfo to check entry stuff inside. But when sched action calls xt_check_target, par.entryinfo is set with NULL. It would cause kernel panic when calling some targets. It can be reproduce with: # tc qd add dev eth1 ingress handle ffff: # tc filter add dev eth1 parent ffff: u32 match u32 0 0 action xt \ -j ECN --ecn-tcp-remove It could also crash kernel when using target CLUSTERIP or TPROXY. By now there's no proper value for par.entryinfo in ipt_init_target, but it can not be set with NULL. This patch is to void all these panics by setting it with an ipt_entry obj with all members = 0. Note that this issue has been there since the very beginning. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/act_ipt.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/net/sched/act_ipt.c b/net/sched/act_ipt.c
index a1aec0a6c789..50030519a89b 100644
--- a/net/sched/act_ipt.c
+++ b/net/sched/act_ipt.c
@@ -41,6 +41,7 @@ static int ipt_init_target(struct xt_entry_target *t, char *table,
{
struct xt_tgchk_param par;
struct xt_target *target;
+ struct ipt_entry e = {};
int ret = 0;
target = xt_request_find_target(AF_INET, t->u.user.name,
@@ -51,6 +52,7 @@ static int ipt_init_target(struct xt_entry_target *t, char *table,
t->u.kernel.target = target;
memset(&par, 0, sizeof(par));
par.table = table;
+ par.entryinfo = &e;
par.target = target;
par.targinfo = t->data;
par.hook_mask = hook;