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Commit a2f4ac78 authored by Linux Build Service Account's avatar Linux Build Service Account Committed by Gerrit - the friendly Code Review server
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Merge "tcp: take care of truncations done by sk_filter()"

parents 5b00a91a 68b87a2b

include/linux/filter.h

+5 −1
Original line number Diff line number Diff line
@@ -421,7 +421,11 @@ static inline void bpf_prog_unlock_ro(struct bpf_prog *fp) 
}

#endif /* CONFIG_DEBUG_SET_MODULE_RONX */



int sk_filter(struct sock *sk, struct sk_buff *skb);

int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap);

static inline int sk_filter(struct sock *sk, struct sk_buff *skb)

{

	return sk_filter_trim_cap(sk, skb, 1);

}



int bpf_prog_select_runtime(struct bpf_prog *fp);

void bpf_prog_free(struct bpf_prog *fp);

include/net/tcp.h

+1 −0
Original line number Diff line number Diff line
@@ -1171,6 +1171,7 @@ static inline void tcp_prequeue_init(struct tcp_sock *tp) 
}



bool tcp_prequeue(struct sock *sk, struct sk_buff *skb);

int tcp_filter(struct sock *sk, struct sk_buff *skb);



#undef STATE_TRACE

net/core/filter.c

+5 −4
Original line number Diff line number Diff line
@@ -52,9 +52,10 @@ 
#include <net/dst.h>



/**

 *	sk_filter - run a packet through a socket filter

 *	sk_filter_trim_cap - run a packet through a socket filter

 *	@sk: sock associated with &sk_buff

 *	@skb: buffer to filter

 *	@cap: limit on how short the eBPF program may trim the packet

 *

 * Run the eBPF program and then cut skb->data to correct size returned by

 * the program. If pkt_len is 0 we toss packet. If skb->len is smaller
@@ -63,7 +64,7 @@ 
 * be accepted or -EPERM if the packet should be tossed.

 *

 */

int sk_filter(struct sock *sk, struct sk_buff *skb)

int sk_filter_trim_cap(struct sock *sk, struct sk_buff *skb, unsigned int cap)

{

	int err;

	struct sk_filter *filter;
@@ -85,13 +86,13 @@ int sk_filter(struct sock *sk, struct sk_buff *skb) 
	if (filter) {

		unsigned int pkt_len = bpf_prog_run_save_cb(filter->prog, skb);



		err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;

		err = pkt_len ? pskb_trim(skb, max(cap, pkt_len)) : -EPERM;

	}

	rcu_read_unlock();



	return err;

}

EXPORT_SYMBOL(sk_filter);

EXPORT_SYMBOL(sk_filter_trim_cap);



static u64 __skb_get_pay_offset(u64 ctx, u64 a, u64 x, u64 r4, u64 r5)

{

net/ipv4/tcp_ipv4.c

+18 −1
Original line number Diff line number Diff line
@@ -1529,6 +1529,21 @@ bool tcp_prequeue(struct sock *sk, struct sk_buff *skb) 
}

EXPORT_SYMBOL(tcp_prequeue);



int tcp_filter(struct sock *sk, struct sk_buff *skb)

{

	struct tcphdr *th = (struct tcphdr *)skb->data;

	unsigned int eaten = skb->len;

	int err;



	err = sk_filter_trim_cap(sk, skb, th->doff * 4);

	if (!err) {

		eaten -= skb->len;

		TCP_SKB_CB(skb)->end_seq -= eaten;

	}

	return err;

}

EXPORT_SYMBOL(tcp_filter);



/*

 *	From tcp_input.c

 */
@@ -1634,8 +1649,10 @@ process: 


	nf_reset(skb);



	if (sk_filter(sk, skb))

	if (tcp_filter(sk, skb))

		goto discard_and_relse;

	th = (const struct tcphdr *)skb->data;

	iph = ip_hdr(skb);



	skb->dev = NULL;

net/ipv6/tcp_ipv6.c

+4 −2
Original line number Diff line number Diff line
@@ -1199,7 +1199,7 @@ static int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb) 
	if (skb->protocol == htons(ETH_P_IP))

		return tcp_v4_do_rcv(sk, skb);



	if (sk_filter(sk, skb))

	if (tcp_filter(sk, skb))

		goto discard;



	/*
@@ -1431,8 +1431,10 @@ process: 
	if (tcp_v6_inbound_md5_hash(sk, skb))

		goto discard_and_relse;



	if (sk_filter(sk, skb))

	if (tcp_filter(sk, skb))

		goto discard_and_relse;

	th = (const struct tcphdr *)skb->data;

	hdr = ipv6_hdr(skb);



	skb->dev = NULL;