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, 77 insertions, 0 deletions

diff --git a/lib/stmp_device.c b/lib/stmp_device.c
new file mode 100644
index 000000000..a4f77b6a9
--- /dev/null
+++ b/lib/stmp_device.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 1999 ARM Limited
+ * Copyright (C) 2000 Deep Blue Solutions Ltd
+ * Copyright 2006-2007,2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Juergen Beisert, kernel@pengutronix.de
+ * Copyright 2009 Ilya Yanok, Emcraft Systems Ltd, yanok@emcraft.com
+ * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
+ */
+
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
+#include <linux/stmp_device.h>
+
+#define STMP_MODULE_CLKGATE	(1 << 30)
+#define STMP_MODULE_SFTRST	(1 << 31)
+
+/*
+ * Clear the bit and poll it cleared.  This is usually called with
+ * a reset address and mask being either SFTRST(bit 31) or CLKGATE
+ * (bit 30).
+ */
+static int stmp_clear_poll_bit(void __iomem *addr, u32 mask)
+{
+	int timeout = 0x400;
+
+	writel(mask, addr + STMP_OFFSET_REG_CLR);
+	udelay(1);
+	while ((readl(addr) & mask) && --timeout)
+		/* nothing */;
+
+	return !timeout;
+}
+
+int stmp_reset_block(void __iomem *reset_addr)
+{
+	int ret;
+	int timeout = 0x400;
+
+	/* clear and poll SFTRST */
+	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
+	if (unlikely(ret))
+		goto error;
+
+	/* clear CLKGATE */
+	writel(STMP_MODULE_CLKGATE, reset_addr + STMP_OFFSET_REG_CLR);
+
+	/* set SFTRST to reset the block */
+	writel(STMP_MODULE_SFTRST, reset_addr + STMP_OFFSET_REG_SET);
+	udelay(1);
+
+	/* poll CLKGATE becoming set */
+	while ((!(readl(reset_addr) & STMP_MODULE_CLKGATE)) && --timeout)
+		/* nothing */;
+	if (unlikely(!timeout))
+		goto error;
+
+	/* clear and poll SFTRST */
+	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_SFTRST);
+	if (unlikely(ret))
+		goto error;
+
+	/* clear and poll CLKGATE */
+	ret = stmp_clear_poll_bit(reset_addr, STMP_MODULE_CLKGATE);
+	if (unlikely(ret))
+		goto error;
+
+	return 0;
+
+error:
+	pr_err("%s(%p): module reset timeout\n", __func__, reset_addr);
+	return -ETIMEDOUT;
+}
+EXPORT_SYMBOL(stmp_reset_block);