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 --- lib/kunit/string-stream.h | 62 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 lib/kunit/string-stream.h (limited to 'lib/kunit/string-stream.h') diff --git a/lib/kunit/string-stream.h b/lib/kunit/string-stream.h new file mode 100644 index 000000000..7be2450c7 --- /dev/null +++ b/lib/kunit/string-stream.h @@ -0,0 +1,62 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * C++ stream style string builder used in KUnit for building messages. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins + */ + +#ifndef _KUNIT_STRING_STREAM_H +#define _KUNIT_STRING_STREAM_H + +#include +#include +#include + +struct string_stream_fragment { + struct list_head node; + char *fragment; +}; + +struct string_stream { + size_t length; + struct list_head fragments; + /* length and fragments are protected by this lock */ + spinlock_t lock; + gfp_t gfp; + bool append_newlines; +}; + +struct kunit; + +struct string_stream *kunit_alloc_string_stream(struct kunit *test, gfp_t gfp); +void kunit_free_string_stream(struct kunit *test, struct string_stream *stream); + +struct string_stream *alloc_string_stream(gfp_t gfp); +void free_string_stream(struct string_stream *stream); + +int __printf(2, 3) string_stream_add(struct string_stream *stream, + const char *fmt, ...); + +int __printf(2, 0) string_stream_vadd(struct string_stream *stream, + const char *fmt, + va_list args); + +void string_stream_clear(struct string_stream *stream); + +char *string_stream_get_string(struct string_stream *stream); + +int string_stream_append(struct string_stream *stream, + struct string_stream *other); + +bool string_stream_is_empty(struct string_stream *stream); + +void string_stream_destroy(struct string_stream *stream); + +static inline void string_stream_set_append_newlines(struct string_stream *stream, + bool append_newlines) +{ + stream->append_newlines = append_newlines; +} + +#endif /* _KUNIT_STRING_STREAM_H */ -- cgit v1.3.1