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, 64 insertions, 0 deletions

diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
new file mode 100644
index 000000000..2dba7f83e
--- /dev/null
+++ b/arch/x86/lib/Makefile
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for x86 specific library files.
+#
+
+# Produces uninteresting flaky coverage.
+KCOV_INSTRUMENT_delay.o	:= n
+
+# KCSAN uses udelay for introducing watchpoint delay; avoid recursion.
+KCSAN_SANITIZE_delay.o := n
+ifdef CONFIG_KCSAN
+# In case KCSAN+lockdep+ftrace are enabled, disable ftrace for delay.o to avoid
+# lockdep -> [other libs] -> KCSAN -> udelay -> ftrace -> lockdep recursion.
+CFLAGS_REMOVE_delay.o = $(CC_FLAGS_FTRACE)
+endif
+
+inat_tables_script = $(srctree)/arch/x86/tools/gen-insn-attr-x86.awk
+inat_tables_maps = $(srctree)/arch/x86/lib/x86-opcode-map.txt
+quiet_cmd_inat_tables = GEN     $@
+      cmd_inat_tables = $(AWK) -f $(inat_tables_script) $(inat_tables_maps) > $@
+
+$(obj)/inat-tables.c: $(inat_tables_script) $(inat_tables_maps)
+	$(call cmd,inat_tables)
+
+$(obj)/inat.o: $(obj)/inat-tables.c
+
+clean-files := inat-tables.c
+
+obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o
+
+lib-y := delay.o misc.o cmdline.o cpu.o
+lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o
+lib-y += memcpy_$(BITS).o
+lib-y += pc-conf-reg.o
+lib-$(CONFIG_ARCH_HAS_COPY_MC) += copy_mc.o copy_mc_64.o
+lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
+lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
+lib-$(CONFIG_FUNCTION_ERROR_INJECTION)	+= error-inject.o
+lib-$(CONFIG_MITIGATION_RETPOLINE) += retpoline.o
+
+obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o
+obj-y += iomem.o
+
+ifeq ($(CONFIG_X86_32),y)
+        obj-y += atomic64_32.o
+        lib-y += atomic64_cx8_32.o
+        lib-y += checksum_32.o
+        lib-y += strstr_32.o
+        lib-y += string_32.o
+        lib-y += memmove_32.o
+        lib-y += cmpxchg8b_emu.o
+ifneq ($(CONFIG_X86_CX8),y)
+        lib-y += atomic64_386_32.o
+endif
+else
+ifneq ($(CONFIG_GENERIC_CSUM),y)
+        lib-y += csum-partial_64.o csum-copy_64.o csum-wrappers_64.o
+endif
+        lib-y += clear_page_64.o copy_page_64.o
+        lib-y += memmove_64.o memset_64.o
+        lib-y += copy_user_64.o copy_user_uncached_64.o
+        lib-y += cmpxchg16b_emu.o
+        lib-y += bhi.o
+endif