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/decompress.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 lib/decompress.c (limited to 'lib/decompress.c') diff --git a/lib/decompress.c b/lib/decompress.c new file mode 100644 index 000000000..778547158 --- /dev/null +++ b/lib/decompress.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * decompress.c + * + * Detect the decompression method based on magic number + */ + +#include + +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#ifndef CONFIG_DECOMPRESS_GZIP +# define gunzip NULL +#endif +#ifndef CONFIG_DECOMPRESS_BZIP2 +# define bunzip2 NULL +#endif +#ifndef CONFIG_DECOMPRESS_LZMA +# define unlzma NULL +#endif +#ifndef CONFIG_DECOMPRESS_XZ +# define unxz NULL +#endif +#ifndef CONFIG_DECOMPRESS_LZO +# define unlzo NULL +#endif +#ifndef CONFIG_DECOMPRESS_LZ4 +# define unlz4 NULL +#endif +#ifndef CONFIG_DECOMPRESS_ZSTD +# define unzstd NULL +#endif + +struct compress_format { + unsigned char magic[2]; + const char *name; + decompress_fn decompressor; +}; + +static const struct compress_format compressed_formats[] __initconst = { + { .magic = {0x1f, 0x8b}, .name = "gzip", .decompressor = gunzip }, + { .magic = {0x1f, 0x9e}, .name = "gzip", .decompressor = gunzip }, + { .magic = {0x42, 0x5a}, .name = "bzip2", .decompressor = bunzip2 }, + { .magic = {0x5d, 0x00}, .name = "lzma", .decompressor = unlzma }, + { .magic = {0xfd, 0x37}, .name = "xz", .decompressor = unxz }, + { .magic = {0x89, 0x4c}, .name = "lzo", .decompressor = unlzo }, + { .magic = {0x02, 0x21}, .name = "lz4", .decompressor = unlz4 }, + { .magic = {0x28, 0xb5}, .name = "zstd", .decompressor = unzstd }, + { /* sentinel */ } +}; + +decompress_fn __init decompress_method(const unsigned char *inbuf, long len, + const char **name) +{ + const struct compress_format *cf; + + if (len < 2) { + if (name) + *name = NULL; + return NULL; /* Need at least this much... */ + } + + pr_debug("Compressed data magic: %#.2x %#.2x\n", inbuf[0], inbuf[1]); + + for (cf = compressed_formats; cf->name; cf++) + if (!memcmp(inbuf, cf->magic, 2)) + break; + + if (name) + *name = cf->name; + return cf->decompressor; +} -- cgit v1.3.1