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, 157 insertions, 0 deletions

diff --git a/block/partitions/mac.c b/block/partitions/mac.c
new file mode 100644
index 000000000..df03ca428
--- /dev/null
+++ b/block/partitions/mac.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  fs/partitions/mac.c
+ *
+ *  Code extracted from drivers/block/genhd.c
+ *  Copyright (C) 1991-1998  Linus Torvalds
+ *  Re-organised Feb 1998 Russell King
+ */
+
+#include <linux/ctype.h>
+#include "check.h"
+#include "mac.h"
+
+#ifdef CONFIG_PPC_PMAC
+#include <asm/machdep.h>
+extern void note_bootable_part(dev_t dev, int part, int goodness);
+#endif
+
+/*
+ * Code to understand MacOS partition tables.
+ */
+
+#ifdef CONFIG_PPC_PMAC
+static inline void mac_fix_string(char *stg, int len)
+{
+	int i;
+
+	for (i = len - 1; i >= 0 && stg[i] == ' '; i--)
+		stg[i] = 0;
+}
+#endif
+
+int mac_partition(struct parsed_partitions *state)
+{
+	Sector sect;
+	unsigned char *data;
+	int slot, blocks_in_map;
+	unsigned secsize, datasize, partoffset;
+#ifdef CONFIG_PPC_PMAC
+	int found_root = 0;
+	int found_root_goodness = 0;
+#endif
+	struct mac_partition *part;
+	struct mac_driver_desc *md;
+
+	/* Get 0th block and look at the first partition map entry. */
+	md = read_part_sector(state, 0, &sect);
+	if (!md)
+		return -1;
+	if (be16_to_cpu(md->signature) != MAC_DRIVER_MAGIC) {
+		put_dev_sector(sect);
+		return 0;
+	}
+	secsize = be16_to_cpu(md->block_size);
+	put_dev_sector(sect);
+
+	/*
+	 * If the "block size" is not a power of 2, things get weird - we might
+	 * end up with a partition straddling a sector boundary, so we wouldn't
+	 * be able to read a partition entry with read_part_sector().
+	 * Real block sizes are probably (?) powers of two, so just require
+	 * that.
+	 */
+	if (!is_power_of_2(secsize))
+		return -1;
+	datasize = round_down(secsize, 512);
+	data = read_part_sector(state, datasize / 512, &sect);
+	if (!data)
+		return -1;
+	partoffset = secsize % 512;
+	if (partoffset + sizeof(*part) > datasize) {
+		put_dev_sector(sect);
+		return -1;
+	}
+	part = (struct mac_partition *) (data + partoffset);
+	if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC) {
+		put_dev_sector(sect);
+		return 0;		/* not a MacOS disk */
+	}
+	blocks_in_map = be32_to_cpu(part->map_count);
+	if (blocks_in_map < 0 || blocks_in_map >= DISK_MAX_PARTS) {
+		put_dev_sector(sect);
+		return 0;
+	}
+
+	if (blocks_in_map >= state->limit)
+		blocks_in_map = state->limit - 1;
+
+	seq_buf_puts(&state->pp_buf, " [mac]");
+	for (slot = 1; slot <= blocks_in_map; ++slot) {
+		int pos = slot * secsize;
+		put_dev_sector(sect);
+		data = read_part_sector(state, pos/512, &sect);
+		if (!data)
+			return -1;
+		part = (struct mac_partition *) (data + pos%512);
+		if (be16_to_cpu(part->signature) != MAC_PARTITION_MAGIC)
+			break;
+		put_partition(state, slot,
+			be32_to_cpu(part->start_block) * (secsize/512),
+			be32_to_cpu(part->block_count) * (secsize/512));
+
+		if (!strncasecmp(part->type, "Linux_RAID", 10))
+			state->parts[slot].flags = ADDPART_FLAG_RAID;
+#ifdef CONFIG_PPC_PMAC
+		/*
+		 * If this is the first bootable partition, tell the
+		 * setup code, in case it wants to make this the root.
+		 */
+		if (machine_is(powermac)) {
+			int goodness = 0;
+
+			mac_fix_string(part->processor, 16);
+			mac_fix_string(part->name, 32);
+			mac_fix_string(part->type, 32);					
+		    
+			if ((be32_to_cpu(part->status) & MAC_STATUS_BOOTABLE)
+			    && strcasecmp(part->processor, "powerpc") == 0)
+				goodness++;
+
+			if (strcasecmp(part->type, "Apple_UNIX_SVR2") == 0
+			    || (strncasecmp(part->type, "Linux", 5) == 0
+			        && strcasecmp(part->type, "Linux_swap") != 0)) {
+				int i, l;
+
+				goodness++;
+				l = strnlen(part->name, sizeof(part->name));
+				if (strncmp(part->name, "/", sizeof(part->name)) == 0)
+					goodness++;
+				for (i = 0; i <= l - 4; ++i) {
+					if (strncasecmp(part->name + i, "root",
+						     4) == 0) {
+						goodness += 2;
+						break;
+					}
+				}
+				if (strncasecmp(part->name, "swap", 4) == 0)
+					goodness--;
+			}
+
+			if (goodness > found_root_goodness) {
+				found_root = slot;
+				found_root_goodness = goodness;
+			}
+		}
+#endif /* CONFIG_PPC_PMAC */
+	}
+#ifdef CONFIG_PPC_PMAC
+	if (found_root_goodness)
+		note_bootable_part(state->disk->part0->bd_dev, found_root,
+				   found_root_goodness);
+#endif
+
+	put_dev_sector(sect);
+	seq_buf_puts(&state->pp_buf, "\n");
+	return 1;
+}