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, 13 insertions, 0 deletions

diff --git a/scripts/subarch.include b/scripts/subarch.include
new file mode 100644
index 000000000..c4592d59d
--- /dev/null
+++ b/scripts/subarch.include
@@ -0,0 +1,13 @@
+# SUBARCH tells the usermode build what the underlying arch is.  That is set
+# first, and if a usermode build is happening, the "ARCH=um" on the command
+# line overrides the setting of ARCH below.  If a native build is happening,
+# then ARCH is assigned, getting whatever value it gets normally, and
+# SUBARCH is subsequently ignored.
+
+SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
+				  -e s/sun4u/sparc64/ \
+				  -e /^arm64$$/!s/arm.*/arm/ -e s/sa110/arm/ \
+				  -e s/s390x/s390/ \
+				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
+				  -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ \
+				  -e s/riscv.*/riscv/ -e s/loongarch.*/loongarch/)