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/kunit/try-catch.h | 63 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 63 insertions(+) create mode 100644 include/kunit/try-catch.h (limited to 'include/kunit/try-catch.h') diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h new file mode 100644 index 000000000..d4e1a5b98 --- /dev/null +++ b/include/kunit/try-catch.h @@ -0,0 +1,63 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * An API to allow a function, that may fail, to be executed, and recover in a + * controlled manner. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins + */ + +#ifndef _KUNIT_TRY_CATCH_H +#define _KUNIT_TRY_CATCH_H + +#include + +typedef void (*kunit_try_catch_func_t)(void *); + +struct kunit; + +/** + * struct kunit_try_catch - provides a generic way to run code which might fail. + * @test: The test case that is currently being executed. + * @try_result: Contains any errno obtained while running test case. + * @try: The function, the test case, to attempt to run. + * @catch: The function called if @try bails out. + * @context: used to pass user data to the try and catch functions. + * + * kunit_try_catch provides a generic, architecture independent way to execute + * an arbitrary function of type kunit_try_catch_func_t which may bail out by + * calling kunit_try_catch_throw(). If kunit_try_catch_throw() is called, @try + * is stopped at the site of invocation and @catch is called. + * + * struct kunit_try_catch provides a generic interface for the functionality + * needed to implement kunit->abort() which in turn is needed for implementing + * assertions. Assertions allow stating a precondition for a test simplifying + * how test cases are written and presented. + * + * Assertions are like expectations, except they abort (call + * kunit_try_catch_throw()) when the specified condition is not met. This is + * useful when you look at a test case as a logical statement about some piece + * of code, where assertions are the premises for the test case, and the + * conclusion is a set of predicates, rather expectations, that must all be + * true. If your premises are violated, it does not makes sense to continue. + */ +struct kunit_try_catch { + /* private: internal use only. */ + struct kunit *test; + int try_result; + kunit_try_catch_func_t try; + kunit_try_catch_func_t catch; + unsigned long timeout; + void *context; +}; + +void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context); + +void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch); + +static inline int kunit_try_catch_get_result(struct kunit_try_catch *try_catch) +{ + return try_catch->try_result; +} + +#endif /* _KUNIT_TRY_CATCH_H */ -- cgit v1.3.1