linux-stable/include/net/esp.h
Steffen Klassert 4aaabbffc3 esp: Fix possible buffer overflow in ESP transformation
[ Upstream commit ebe48d368e ]

The maximum message size that can be send is bigger than
the  maximum site that skb_page_frag_refill can allocate.
So it is possible to write beyond the allocated buffer.

Fix this by doing a fallback to COW in that case.

v2:

Avoid get get_order() costs as suggested by Linus Torvalds.

Fixes: cac2661c53 ("esp4: Avoid skb_cow_data whenever possible")
Fixes: 03e2a30f6a ("esp6: Avoid skb_cow_data whenever possible")
Reported-by: valis <sec@valis.email>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-03-16 14:23:36 +01:00

51 lines
1.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _NET_ESP_H
#define _NET_ESP_H
#include <linux/skbuff.h>
#define ESP_SKB_FRAG_MAXSIZE (PAGE_SIZE << SKB_FRAG_PAGE_ORDER)
struct ip_esp_hdr;
static inline struct ip_esp_hdr *ip_esp_hdr(const struct sk_buff *skb)
{
return (struct ip_esp_hdr *)skb_transport_header(skb);
}
static inline void esp_output_fill_trailer(u8 *tail, int tfclen, int plen, __u8 proto)
{
/* Fill padding... */
if (tfclen) {
memset(tail, 0, tfclen);
tail += tfclen;
}
do {
int i;
for (i = 0; i < plen - 2; i++)
tail[i] = i + 1;
} while (0);
tail[plen - 2] = plen - 2;
tail[plen - 1] = proto;
}
struct esp_info {
struct ip_esp_hdr *esph;
__be64 seqno;
int tfclen;
int tailen;
int plen;
int clen;
int len;
int nfrags;
__u8 proto;
bool inplace;
};
int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp_input_done2(struct sk_buff *skb, int err);
int esp6_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp6_output_tail(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *esp);
int esp6_input_done2(struct sk_buff *skb, int err);
#endif