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, 65 insertions, 0 deletions

diff --git a/include/xen/hvm.h b/include/xen/hvm.h
new file mode 100644
index 000000000..8da7a6747
--- /dev/null
+++ b/include/xen/hvm.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Simple wrappers around HVM functions */
+#ifndef XEN_HVM_H__
+#define XEN_HVM_H__
+
+#include <xen/interface/hvm/params.h>
+#include <asm/xen/hypercall.h>
+
+static const char *param_name(int op)
+{
+#define PARAM(x) [HVM_PARAM_##x] = #x
+	static const char *const names[] = {
+		PARAM(CALLBACK_IRQ),
+		PARAM(STORE_PFN),
+		PARAM(STORE_EVTCHN),
+		PARAM(PAE_ENABLED),
+		PARAM(IOREQ_PFN),
+		PARAM(BUFIOREQ_PFN),
+		PARAM(TIMER_MODE),
+		PARAM(HPET_ENABLED),
+		PARAM(IDENT_PT),
+		PARAM(DM_DOMAIN),
+		PARAM(ACPI_S_STATE),
+		PARAM(VM86_TSS),
+		PARAM(VPT_ALIGN),
+		PARAM(CONSOLE_PFN),
+		PARAM(CONSOLE_EVTCHN),
+	};
+#undef PARAM
+
+	if (op >= ARRAY_SIZE(names))
+		return "unknown";
+
+	if (!names[op])
+		return "reserved";
+
+	return names[op];
+}
+static inline int hvm_get_parameter(int idx, uint64_t *value)
+{
+	struct xen_hvm_param xhv;
+	int r;
+
+	xhv.domid = DOMID_SELF;
+	xhv.index = idx;
+	r = HYPERVISOR_hvm_op(HVMOP_get_param, &xhv);
+	if (r < 0) {
+		pr_err("Cannot get hvm parameter %s (%d): %d!\n",
+		       param_name(idx), idx, r);
+		return r;
+	}
+	*value = xhv.value;
+	return r;
+}
+
+#define HVM_CALLBACK_VIA_TYPE_VECTOR 0x2
+#define HVM_CALLBACK_VIA_TYPE_SHIFT 56
+#define HVM_CALLBACK_VECTOR(x) (((uint64_t)HVM_CALLBACK_VIA_TYPE_VECTOR)<<\
+		HVM_CALLBACK_VIA_TYPE_SHIFT | (x))
+
+void xen_setup_callback_vector(void);
+
+int xen_set_upcall_vector(unsigned int cpu);
+
+#endif /* XEN_HVM_H__ */