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, 43 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/grackle.c b/arch/powerpc/sysdev/grackle.c
new file mode 100644
index 000000000..7dce8278b
--- /dev/null
+++ b/arch/powerpc/sysdev/grackle.c
@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Functions for setting up and using a MPC106 northbridge
+ * Extracted from arch/powerpc/platforms/powermac/pci.c.
+ *
+ * Copyright (C) 2003 Benjamin Herrenschmuidt (benh@kernel.crashing.org)
+ * Copyright (C) 1997 Paul Mackerras (paulus@samba.org)
+ */
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/of.h>
+
+#include <asm/io.h>
+#include <asm/pci-bridge.h>
+#include <asm/grackle.h>
+
+#define GRACKLE_CFA(b, d, o)	(0x80 | ((b) << 8) | ((d) << 16) \
+				 | (((o) & ~3) << 24))
+
+#define GRACKLE_PICR1_LOOPSNOOP		0x00000010
+
+static inline void grackle_set_loop_snoop(struct pci_controller *bp, int enable)
+{
+	unsigned int val;
+
+	out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
+	val = in_le32(bp->cfg_data);
+	val = enable? (val | GRACKLE_PICR1_LOOPSNOOP) :
+		(val & ~GRACKLE_PICR1_LOOPSNOOP);
+	out_be32(bp->cfg_addr, GRACKLE_CFA(0, 0, 0xa8));
+	out_le32(bp->cfg_data, val);
+	(void)in_le32(bp->cfg_data);
+}
+
+void __init setup_grackle(struct pci_controller *hose)
+{
+	setup_indirect_pci(hose, 0xfec00000, 0xfee00000, 0);
+	if (of_machine_is_compatible("PowerMac1,1"))
+		pci_add_flags(PCI_REASSIGN_ALL_BUS);
+	if (of_machine_is_compatible("AAPL,PowerBook1998"))
+		grackle_set_loop_snoop(hose, 1);
+}