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, 95 insertions, 0 deletions

diff --git a/include/xen/interface/xenpmu.h b/include/xen/interface/xenpmu.h
new file mode 100644
index 000000000..e2ee73d91
--- /dev/null
+++ b/include/xen/interface/xenpmu.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: MIT */
+#ifndef __XEN_PUBLIC_XENPMU_H__
+#define __XEN_PUBLIC_XENPMU_H__
+
+#include "xen.h"
+
+#define XENPMU_VER_MAJ    0
+#define XENPMU_VER_MIN    1
+
+/*
+ * ` enum neg_errnoval
+ * ` HYPERVISOR_xenpmu_op(enum xenpmu_op cmd, struct xenpmu_params *args);
+ *
+ * @cmd  == XENPMU_* (PMU operation)
+ * @args == struct xenpmu_params
+ */
+/* ` enum xenpmu_op { */
+#define XENPMU_mode_get        0 /* Also used for getting PMU version */
+#define XENPMU_mode_set        1
+#define XENPMU_feature_get     2
+#define XENPMU_feature_set     3
+#define XENPMU_init            4
+#define XENPMU_finish          5
+#define XENPMU_lvtpc_set       6
+#define XENPMU_flush           7
+
+/* ` } */
+
+/* Parameters structure for HYPERVISOR_xenpmu_op call */
+struct xen_pmu_params {
+	/* IN/OUT parameters */
+	struct {
+		uint32_t maj;
+		uint32_t min;
+	} version;
+	uint64_t val;
+
+	/* IN parameters */
+	uint32_t vcpu;
+	uint32_t pad;
+};
+
+/* PMU modes:
+ * - XENPMU_MODE_OFF:   No PMU virtualization
+ * - XENPMU_MODE_SELF:  Guests can profile themselves
+ * - XENPMU_MODE_HV:    Guests can profile themselves, dom0 profiles
+ *                      itself and Xen
+ * - XENPMU_MODE_ALL:   Only dom0 has access to VPMU and it profiles
+ *                      everyone: itself, the hypervisor and the guests.
+ */
+#define XENPMU_MODE_OFF           0
+#define XENPMU_MODE_SELF          (1<<0)
+#define XENPMU_MODE_HV            (1<<1)
+#define XENPMU_MODE_ALL           (1<<2)
+
+/*
+ * PMU features:
+ * - XENPMU_FEATURE_INTEL_BTS: Intel BTS support (ignored on AMD)
+ */
+#define XENPMU_FEATURE_INTEL_BTS  1
+
+/*
+ * Shared PMU data between hypervisor and PV(H) domains.
+ *
+ * The hypervisor fills out this structure during PMU interrupt and sends an
+ * interrupt to appropriate VCPU.
+ * Architecture-independent fields of xen_pmu_data are WO for the hypervisor
+ * and RO for the guest but some fields in xen_pmu_arch can be writable
+ * by both the hypervisor and the guest (see arch-$arch/pmu.h).
+ */
+struct xen_pmu_data {
+	/* Interrupted VCPU */
+	uint32_t vcpu_id;
+
+	/*
+	 * Physical processor on which the interrupt occurred. On non-privileged
+	 * guests set to vcpu_id;
+	 */
+	uint32_t pcpu_id;
+
+	/*
+	 * Domain that was interrupted. On non-privileged guests set to
+	 * DOMID_SELF.
+	 * On privileged guests can be DOMID_SELF, DOMID_XEN, or, when in
+	 * XENPMU_MODE_ALL mode, domain ID of another domain.
+	 */
+	domid_t  domain_id;
+
+	uint8_t pad[6];
+
+	/* Architecture-specific information */
+	struct xen_pmu_arch pmu;
+};
+
+#endif /* __XEN_PUBLIC_XENPMU_H__ */