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, 41 insertions, 0 deletions

diff --git a/arch/mips/Makefile.postlink b/arch/mips/Makefile.postlink
new file mode 100644
index 000000000..ea0add7d5
--- /dev/null
+++ b/arch/mips/Makefile.postlink
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+# ===========================================================================
+# Post-link MIPS pass
+# ===========================================================================
+#
+# 1. Check that Loongson3 LL/SC workarounds are applied correctly
+# 2. Insert relocations into vmlinux
+
+PHONY := __archpost
+__archpost:
+
+-include include/config/auto.conf
+include $(srctree)/scripts/Kbuild.include
+
+CMD_LS3_LLSC = arch/mips/tools/loongson3-llsc-check
+quiet_cmd_ls3_llsc = LLSCCHK $@
+      cmd_ls3_llsc = $(CMD_LS3_LLSC) $@
+
+CMD_RELOCS = arch/mips/boot/tools/relocs
+quiet_cmd_relocs = RELOCS  $@
+      cmd_relocs = $(CMD_RELOCS) $@
+
+# `@true` prevents complaint when there is nothing to be done
+
+vmlinux vmlinux.unstripped: FORCE
+	@true
+ifeq ($(CONFIG_CPU_LOONGSON3_WORKAROUNDS),y)
+	$(call if_changed,ls3_llsc)
+endif
+ifeq ($(CONFIG_RELOCATABLE),y)
+	$(call if_changed,relocs)
+endif
+
+clean:
+	@true
+
+PHONY += FORCE clean
+
+FORCE:
+
+.PHONY: $(PHONY)