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, 53 insertions, 0 deletions

diff --git a/arch/powerpc/Makefile.postlink b/arch/powerpc/Makefile.postlink
new file mode 100644
index 000000000..bb601be36
--- /dev/null
+++ b/arch/powerpc/Makefile.postlink
@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: GPL-2.0
+# ===========================================================================
+# Post-link powerpc pass
+# ===========================================================================
+#
+# 1. Check that vmlinux relocations look sane
+
+PHONY := __archpost
+__archpost:
+
+-include include/config/auto.conf
+include $(srctree)/scripts/Kbuild.include
+
+quiet_cmd_head_check = CHKHEAD $@
+      cmd_head_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/head_check.sh "$(NM)" "$@"
+
+quiet_cmd_relocs_check = CHKREL  $@
+ifdef CONFIG_PPC_BOOK3S_64
+      cmd_relocs_check =						\
+	$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$(NM)" "$@" ; \
+	$(BASH) $(srctree)/arch/powerpc/tools/unrel_branch_check.sh "$(OBJDUMP)" "$(NM)" "$@"
+else
+      cmd_relocs_check =						\
+	$(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/relocs_check.sh "$(OBJDUMP)" "$(NM)" "$@"
+endif
+
+quiet_cmd_ftrace_check = CHKFTRC $@
+      cmd_ftrace_check = $(CONFIG_SHELL) $(srctree)/arch/powerpc/tools/ftrace_check.sh "$(NM)" "$@"
+
+# `@true` prevents complaint when there is nothing to be done
+
+vmlinux: FORCE
+	@true
+ifdef CONFIG_PPC64
+	$(call cmd,head_check)
+endif
+ifdef CONFIG_RELOCATABLE
+	$(call if_changed,relocs_check)
+endif
+ifdef CONFIG_FUNCTION_TRACER
+ifndef CONFIG_PPC64_ELF_ABI_V1
+	$(call cmd,ftrace_check)
+endif
+endif
+
+clean:
+	rm -f .tmp_symbols.txt
+
+PHONY += FORCE clean
+
+FORCE:
+
+.PHONY: $(PHONY)