Commit 62b656e4 authored by Ranganath V N's avatar Ranganath V N Committed by Paolo Abeni
Browse files

net: sched: act_connmark: initialize struct tc_ife to fix kernel leak 



In tcf_connmark_dump(), the variable 'opt' was partially initialized using a
designatied initializer. While the padding bytes are reamined
uninitialized. nla_put() copies the entire structure into a
netlink message, these uninitialized bytes leaked to userspace.

Initialize the structure with memset before assigning its fields
to ensure all members and padding are cleared prior to beign copied.

Reported-by: default avatar <syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=0c85cae3350b7d486aee


Tested-by: default avatar <syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com>
Fixes: 22a5dc0e ("net: sched: Introduce connmark action")
Signed-off-by: default avatarRanganath V N <vnranganath.20@gmail.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251109091336.9277-2-vnranganath.20@gmail.com


Acked-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 60e6489f

net/sched/act_connmark.c

+7 −5
Original line number Diff line number Diff line
@@ -195,13 +195,15 @@ static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a, 
	const struct tcf_connmark_info *ci = to_connmark(a);

	unsigned char *b = skb_tail_pointer(skb);

	const struct tcf_connmark_parms *parms;

	struct tc_connmark opt = {

		.index   = ci->tcf_index,

		.refcnt  = refcount_read(&ci->tcf_refcnt) - ref,

		.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,

	};

	struct tc_connmark opt;

	struct tcf_t t;



	memset(&opt, 0, sizeof(opt));



	opt.index   = ci->tcf_index;

	opt.refcnt  = refcount_read(&ci->tcf_refcnt) - ref;

	opt.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind;



	rcu_read_lock();

	parms = rcu_dereference(ci->parms);