From ff917923f4fb9c83717ba135ee47d7e4c1567bb7 Mon Sep 17 00:00:00 2001 From: Muhammad Bilal Date: Tue, 28 Jul 2026 17:54:55 +0500 Subject: staging: rtl8723bs: fix OOB read in rtw_action_frame_parse() rtw_action_frame_parse() takes a frame_len parameter but never actually checks it before indexing into the frame body: const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr); ... c = frame_body[0]; ... a = frame_body[1]; frame_body already points 24 bytes (sizeof(struct ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and frame_body[1] requires frame_len >= 26. A management action frame shorter than that (e.g. exactly 24 bytes, the minimum a malicious peer can send) causes a 1-2 byte out-of-bounds read. This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass attacker/user-influenced frame buffers and lengths straight through. Add the missing length check before frame_body is dereferenced. Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable@vger.kernel.org Signed-off-by: Muhammad Bilal Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com Signed-off-by: Greg Kroah-Hartman --- lib/crypto/tests/test-utils.h | 111 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) create mode 100644 lib/crypto/tests/test-utils.h (limited to 'lib/crypto/tests/test-utils.h') diff --git a/lib/crypto/tests/test-utils.h b/lib/crypto/tests/test-utils.h new file mode 100644 index 000000000..73ca21f91 --- /dev/null +++ b/lib/crypto/tests/test-utils.h @@ -0,0 +1,111 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Test utility functions shared by the crypto library tests. + * + * For now this is simply a header that's included into the KUnit test suites + * that need it. If this gets too large it could be made its own translation + * unit and libcrypto_test_utils module, but that seems overkill for now. + */ +#ifndef LIB_CRYPTO_TEST_UTILS_H +#define LIB_CRYPTO_TEST_UTILS_H + +#include +#include +#include +#include +#include + +static u64 random_seed; + +static __maybe_unused void action_free_guarded_buf(void *buf) +{ + vfree(buf); +} + +/* + * Allocate a KUnit-managed buffer that has length @size bytes (> 0) immediately + * followed by an unmapped page, and assert that the allocation succeeds. + */ +static __maybe_unused void *alloc_guarded_buf(struct kunit *test, size_t size) +{ + size_t full_size = round_up(size, PAGE_SIZE); + void *buf = vmalloc(full_size); + + KUNIT_ASSERT_NOT_NULL(test, buf); + KUNIT_ASSERT_EQ(test, 0, + kunit_add_action_or_reset(test, action_free_guarded_buf, + buf)); + return buf + full_size - size; +} + +static __maybe_unused void *alloc_buf(struct kunit *test, size_t size) +{ + void *buf = kunit_kmalloc(test, size, GFP_KERNEL); + + KUNIT_ASSERT_NOT_NULL(test, buf); + return buf; +} + +static __maybe_unused void *memdup_buf(struct kunit *test, const void *src, + size_t size) +{ + void *dst = alloc_buf(test, size); + + return memcpy(dst, src, size); +} + +/* + * This is a simple linear congruential generator. It is used only for testing, + * which does not require cryptographically secure random numbers. A hard-coded + * algorithm is used instead of so that it matches the + * algorithm used by the test vector generation script. This allows the input + * data in random test vectors to be concisely stored as just the seed. + */ +static __maybe_unused u32 rand32(void) +{ + random_seed = (random_seed * 25214903917 + 11) & ((1ULL << 48) - 1); + return random_seed >> 16; +} + +static __maybe_unused void rand_bytes(u8 *out, size_t len) +{ + for (size_t i = 0; i < len; i++) + out[i] = rand32(); +} + +static __maybe_unused void rand_bytes_seeded_from_len(u8 *out, size_t len) +{ + random_seed = len; + rand_bytes(out, len); +} + +static __maybe_unused bool rand_bool(void) +{ + return rand32() % 2; +} + +/* Generate a random length, preferring small lengths. */ +static __maybe_unused size_t rand_length(size_t max_len) +{ + size_t len; + + switch (rand32() % 3) { + case 0: + len = rand32() % 128; + break; + case 1: + len = rand32() % 3072; + break; + default: + len = rand32(); + break; + } + return len % (max_len + 1); +} + +static __maybe_unused size_t rand_offset(size_t max_offset) +{ + return min(rand32() % 128, max_offset); +} + +#endif /* LIB_CRYPTO_TEST_UTILS_H */ -- cgit v1.3.1