staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted

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 <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 115 insertions, 0 deletions

diff --git a/tools/testing/memblock/README b/tools/testing/memblock/README
new file mode 100644
index 000000000..b435f48d8
--- /dev/null
+++ b/tools/testing/memblock/README
@@ -0,0 +1,115 @@
+==================
+Memblock simulator
+==================
+
+Introduction
+============
+
+Memblock is a boot time memory allocator[1] that manages memory regions before
+the actual memory management is initialized. Its APIs allow to register physical
+memory regions, mark them as available or reserved, allocate a block of memory
+within the requested range and/or in specific NUMA node, and many more.
+
+Because it is used so early in the booting process, testing and debugging it is
+difficult. This test suite, usually referred as memblock simulator, is
+an attempt at testing the memblock mechanism. It runs one monolithic test that
+consist of a series of checks that exercise both the basic operations and
+allocation functionalities of memblock. The main data structure of the boot time
+memory allocator is initialized at the build time, so the checks here reuse its
+instance throughout the duration of the test. To ensure that tests don't affect
+each other, region arrays are reset in between.
+
+As this project uses the actual memblock code and has to run in user space,
+some of the kernel definitions were stubbed by the initial commit that
+introduced memblock simulator (commit 16802e55dea9 ("memblock tests: Add
+skeleton of the memblock simulator")) and a few preparation commits just
+before it. Most of them don't match the kernel implementation, so one should
+consult them first before making any significant changes to the project.
+
+Usage
+=====
+
+To run the tests, build the main target and run it:
+
+$ make && ./main
+
+A successful run produces no output. It is possible to control the behavior
+by passing options from command line. For example, to include verbose output,
+append the `-v` options when you run the tests:
+
+$ ./main -v
+
+This will print information about which functions are being tested and the
+number of test cases that passed.
+
+For the full list of options from command line, see `./main --help`.
+
+It is also possible to override different configuration parameters to change
+the test functions. For example, to simulate enabled NUMA, use:
+
+$ make NUMA=1
+
+For the full list of build options, see `make help`.
+
+Project structure
+=================
+
+The project has one target, main, which calls a group of checks for basic and
+allocation functions. Tests for each group are defined in dedicated files, as it
+can be seen here:
+
+memblock
+|-- asm       ------------------,
+|-- lib                         |-- implement function and struct stubs
+|-- linux     ------------------'
+|-- scripts
+|    |-- Makefile.include        -- handles `make` parameters
+|-- tests
+|    |-- alloc_api.(c|h)         -- memblock_alloc tests
+|    |-- alloc_helpers_api.(c|h) -- memblock_alloc_from tests
+|    |-- alloc_nid_api.(c|h)     -- memblock_alloc_try_nid tests
+|    |-- basic_api.(c|h)         -- memblock_add/memblock_reserve/... tests
+|    |-- common.(c|h)            -- helper functions for resetting memblock;
+|-- main.c        --------------.   dummy physical memory definition
+|-- Makefile                     `- test runner
+|-- README
+|-- TODO
+|-- .gitignore
+
+Simulating physical memory
+==========================
+
+Some allocation functions clear the memory in the process, so it is required for
+memblock to track valid memory ranges. To achieve this, the test suite registers
+with memblock memory stored by test_memory struct. It is a small wrapper that
+points to a block of memory allocated via malloc. For each group of allocation
+tests, dummy physical memory is allocated, added to memblock, and then released
+at the end of the test run. The structure of a test runner checking allocation
+functions is as follows:
+
+int memblock_alloc_foo_checks(void)
+{
+	reset_memblock_attributes();     /* data structure reset */
+	dummy_physical_memory_init();    /* allocate and register memory */
+
+	(...allocation checks...)
+
+	dummy_physical_memory_cleanup(); /* free the memory */
+}
+
+There's no need to explicitly free the dummy memory from memblock via
+memblock_free() call. The entry will be erased by reset_memblock_regions(),
+called at the beginning of each test.
+
+Known issues
+============
+
+1. Tests for memblock_alloc_low() can't be easily implemented. The function uses
+   ARCH_LOW_ADDRESS_LIMIT marco, which can't be changed to point at the low
+   memory of the memory_block.
+
+References
+==========
+
+1. Boot time memory management documentation page:
+   https://www.kernel.org/doc/html/latest/core-api/boot-time-mm.html