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 --- tools/testing/shared/maple-shared.h | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 tools/testing/shared/maple-shared.h (limited to 'tools/testing/shared/maple-shared.h') diff --git a/tools/testing/shared/maple-shared.h b/tools/testing/shared/maple-shared.h new file mode 100644 index 000000000..2a1e9a859 --- /dev/null +++ b/tools/testing/shared/maple-shared.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +#ifndef __MAPLE_SHARED_H__ +#define __MAPLE_SHARED_H__ + +#define CONFIG_DEBUG_MAPLE_TREE +#define CONFIG_MAPLE_SEARCH +#define MAPLE_32BIT (MAPLE_NODE_SLOTS > 31) +#include "shared.h" +#include +#include +#include "linux/init.h" + +void maple_rcu_cb(struct rcu_head *head); +#define rcu_cb maple_rcu_cb + +#define kfree_rcu(_struct, _memb) \ +do { \ + typeof(_struct) _p_struct = (_struct); \ + \ + call_rcu(&((_p_struct)->_memb), rcu_cb); \ +} while(0); + + +#endif /* __MAPLE_SHARED_H__ */ -- cgit v1.3.1