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/psample.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 include/net/psample.h (limited to 'include/net/psample.h') diff --git a/include/net/psample.h b/include/net/psample.h new file mode 100644 index 000000000..5071b5fc2 --- /dev/null +++ b/include/net/psample.h @@ -0,0 +1,56 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_PSAMPLE_H +#define __NET_PSAMPLE_H + +#include +#include + +struct psample_group { + struct list_head list; + struct net *net; + u32 group_num; + u32 refcount; + u32 seq; + struct rcu_head rcu; +}; + +struct psample_metadata { + u32 trunc_size; + int in_ifindex; + int out_ifindex; + u16 out_tc; + u64 out_tc_occ; /* bytes */ + u64 latency; /* nanoseconds */ + u8 out_tc_valid:1, + out_tc_occ_valid:1, + latency_valid:1, + rate_as_probability:1, + unused:4; + const u8 *user_cookie; + u32 user_cookie_len; +}; + +struct psample_group *psample_group_get(struct net *net, u32 group_num); +void psample_group_take(struct psample_group *group); +void psample_group_put(struct psample_group *group); + +struct sk_buff; + +#if IS_ENABLED(CONFIG_PSAMPLE) + +void psample_sample_packet(struct psample_group *group, + const struct sk_buff *skb, u32 sample_rate, + const struct psample_metadata *md); + +#else + +static inline void psample_sample_packet(struct psample_group *group, + const struct sk_buff *skb, + u32 sample_rate, + const struct psample_metadata *md) +{ +} + +#endif + +#endif /* __NET_PSAMPLE_H */ -- cgit v1.3.1