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/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