From 33a154a96e71a34a1bcca9f40da343dbbf7b38b4 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 1 Oct 2026 14:52:55 +0000 Subject: selftests/bpf: Test packet range of pointers sharing an id Add tests where two packet pointers share an id and tightening one pointer's umax from its var_off would put it less than their constant distance from the other's umax: with an index & 0x38 capped at 50, the base pointer keeps umax 50, so the pointer 8 bytes further on must keep umax 58, even though its known bits allow at most 56. These refused a valid program or accepted an out-of-bounds access before the fix: - check the advanced copy, load through the base: valid, was refused; - check the base, load the byte at base + 1 through a copy advanced by 8: was accepted; - check base + 4, load 4 bytes at base + 2 through base + 8: reads two bytes past the checked range, was accepted; - the same as the second with data_meta pointers checked against data: was accepted. These pass with and without the fix and cover nearby paths: - subtract an unknown scalar from a checked pointer and load below it (the range is kept across a new id); - reach a load through two paths whose checks cover 8 and 7 bytes after the loaded pointer; the second path must not be pruned by the first; - spill a copy of a pointer, check the pointer, fill the copy and load one byte past the checked range: the load is refused, and the copy has the range of the check. Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com Signed-off-by: Kumar Kartikeya Dwivedi --- include/net/esp.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 include/net/esp.h (limited to 'include/net/esp.h') diff --git a/include/net/esp.h b/include/net/esp.h new file mode 100644 index 000000000..322950727 --- /dev/null +++ b/include/net/esp.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _NET_ESP_H +#define _NET_ESP_H + +#include + +struct ip_esp_hdr; +struct xfrm_state; + +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 -- cgit v1.3.1