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, 34 insertions, 0 deletions

diff --git a/arch/arm64/tools/Makefile b/arch/arm64/tools/Makefile
new file mode 100644
index 000000000..a94b3d9ca
--- /dev/null
+++ b/arch/arm64/tools/Makefile
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+
+gen := arch/$(ARCH)/include/generated
+kapi := $(gen)/asm
+
+kapisyshdr-y := cpucap-defs.h kernel-hwcap.h sysreg-defs.h
+
+kapi-hdrs-y := $(addprefix $(kapi)/, $(kapisyshdr-y))
+
+targets += $(addprefix ../../../, $(kapi-hdrs-y))
+
+PHONY += kapi
+
+all: $(syscall64) kapi
+
+kapi:   $(kapi-hdrs-y)
+
+quiet_cmd_gen_cpucaps = GEN     $@
+      cmd_gen_cpucaps = mkdir -p $(dir $@); $(AWK) -f $(real-prereqs) > $@
+
+quiet_cmd_gen_kernel_hwcap = GEN     $@
+      cmd_gen_kernel_hwcap = mkdir -p $(dir $@); /bin/sh -e $(real-prereqs) > $@
+
+quiet_cmd_gen_sysreg = GEN     $@
+      cmd_gen_sysreg = mkdir -p $(dir $@); $(AWK) -f $(real-prereqs) > $@
+
+$(kapi)/cpucap-defs.h: $(src)/gen-cpucaps.awk $(src)/cpucaps FORCE
+	$(call if_changed,gen_cpucaps)
+
+$(kapi)/kernel-hwcap.h: $(src)/gen-kernel-hwcaps.sh $(srctree)/arch/arm64/include/uapi/asm/hwcap.h FORCE
+	$(call if_changed,gen_kernel_hwcap)
+
+$(kapi)/sysreg-defs.h: $(src)/gen-sysreg.awk $(src)/sysreg FORCE
+	$(call if_changed,gen_sysreg)