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, 288 insertions, 0 deletions

diff --git a/drivers/video/fbdev/sbuslib.c b/drivers/video/fbdev/sbuslib.c
new file mode 100644
index 000000000..dd2002d08
--- /dev/null
+++ b/drivers/video/fbdev/sbuslib.c
@@ -0,0 +1,288 @@
+// SPDX-License-Identifier: GPL-2.0
+/* sbuslib.c: Helper library for SBUS framebuffer drivers.
+ *
+ * Copyright (C) 2003 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/compat.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/fb.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+#include <linux/of.h>
+
+#include <asm/fbio.h>
+
+#include "sbuslib.h"
+
+void sbusfb_fill_var(struct fb_var_screeninfo *var, struct device_node *dp,
+		     int bpp)
+{
+	memset(var, 0, sizeof(*var));
+
+	var->xres = of_getintprop_default(dp, "width", 1152);
+	var->yres = of_getintprop_default(dp, "height", 900);
+	var->xres_virtual = var->xres;
+	var->yres_virtual = var->yres;
+	var->bits_per_pixel = bpp;
+}
+
+EXPORT_SYMBOL(sbusfb_fill_var);
+
+static unsigned long sbusfb_mmapsize(long size, unsigned long fbsize)
+{
+	if (size == SBUS_MMAP_EMPTY) return 0;
+	if (size >= 0) return size;
+	return fbsize * (-size);
+}
+
+int sbusfb_mmap_helper(const struct sbus_mmap_map *map,
+		       unsigned long physbase,
+		       unsigned long fbsize,
+		       unsigned long iospace,
+		       struct vm_area_struct *vma)
+{
+	unsigned int size, page, r, map_size;
+	unsigned long map_offset = 0;
+	unsigned long off;
+	int i;
+
+	if (!(vma->vm_flags & (VM_SHARED | VM_MAYSHARE)))
+		return -EINVAL;
+
+	size = vma->vm_end - vma->vm_start;
+	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
+		return -EINVAL;
+
+	off = vma->vm_pgoff << PAGE_SHIFT;
+
+	/* VM_IO | VM_DONTEXPAND | VM_DONTDUMP are set by remap_pfn_range() */
+
+	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	/* Each page, see which map applies */
+	for (page = 0; page < size; ){
+		map_size = 0;
+		for (i = 0; map[i].size; i++)
+			if (map[i].voff == off+page) {
+				map_size = sbusfb_mmapsize(map[i].size, fbsize);
+#ifdef __sparc_v9__
+#define POFF_MASK	(PAGE_MASK|0x1UL)
+#else
+#define POFF_MASK	(PAGE_MASK)
+#endif
+				map_offset = (physbase + map[i].poff) & POFF_MASK;
+				break;
+			}
+		if (!map_size) {
+			page += PAGE_SIZE;
+			continue;
+		}
+		if (page + map_size > size)
+			map_size = size - page;
+		r = io_remap_pfn_range(vma,
+					vma->vm_start + page,
+					MK_IOSPACE_PFN(iospace,
+						map_offset >> PAGE_SHIFT),
+					map_size,
+					vma->vm_page_prot);
+		if (r)
+			return -EAGAIN;
+		page += map_size;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(sbusfb_mmap_helper);
+
+int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
+			struct fb_info *info,
+			int type, int fb_depth, unsigned long fb_size)
+{
+	switch(cmd) {
+	case FBIOGTYPE: {
+		struct fbtype __user *f = (struct fbtype __user *) arg;
+
+		if (put_user(type, &f->fb_type) ||
+		    put_user(info->var.yres, &f->fb_height) ||
+		    put_user(info->var.xres, &f->fb_width) ||
+		    put_user(fb_depth, &f->fb_depth) ||
+		    put_user(0, &f->fb_cmsize) ||
+		    put_user(fb_size, &f->fb_cmsize))
+			return -EFAULT;
+		return 0;
+	}
+	case FBIOPUTCMAP_SPARC: {
+		struct fbcmap __user *c = (struct fbcmap __user *) arg;
+		struct fb_cmap cmap;
+		u16 red, green, blue;
+		u8 red8, green8, blue8;
+		unsigned char __user *ured;
+		unsigned char __user *ugreen;
+		unsigned char __user *ublue;
+		unsigned int index, count, i;
+
+		if (get_user(index, &c->index) ||
+		    get_user(count, &c->count) ||
+		    get_user(ured, &c->red) ||
+		    get_user(ugreen, &c->green) ||
+		    get_user(ublue, &c->blue))
+			return -EFAULT;
+
+		cmap.len = 1;
+		cmap.red = &red;
+		cmap.green = &green;
+		cmap.blue = &blue;
+		cmap.transp = NULL;
+		for (i = 0; i < count; i++) {
+			int err;
+
+			if (get_user(red8, &ured[i]) ||
+			    get_user(green8, &ugreen[i]) ||
+			    get_user(blue8, &ublue[i]))
+				return -EFAULT;
+
+			red = red8 << 8;
+			green = green8 << 8;
+			blue = blue8 << 8;
+
+			cmap.start = index + i;
+			err = fb_set_cmap(&cmap, info);
+			if (err)
+				return err;
+		}
+		return 0;
+	}
+	case FBIOGETCMAP_SPARC: {
+		struct fbcmap __user *c = (struct fbcmap __user *) arg;
+		unsigned char __user *ured;
+		unsigned char __user *ugreen;
+		unsigned char __user *ublue;
+		struct fb_cmap *cmap = &info->cmap;
+		unsigned int index, count, i;
+		u8 red, green, blue;
+
+		if (get_user(index, &c->index) ||
+		    get_user(count, &c->count) ||
+		    get_user(ured, &c->red) ||
+		    get_user(ugreen, &c->green) ||
+		    get_user(ublue, &c->blue))
+			return -EFAULT;
+
+		if (index > cmap->len || count > cmap->len - index)
+			return -EINVAL;
+
+		for (i = 0; i < count; i++) {
+			red = cmap->red[index + i] >> 8;
+			green = cmap->green[index + i] >> 8;
+			blue = cmap->blue[index + i] >> 8;
+			if (put_user(red, &ured[i]) ||
+			    put_user(green, &ugreen[i]) ||
+			    put_user(blue, &ublue[i]))
+				return -EFAULT;
+		}
+		return 0;
+	}
+	default:
+		return -EINVAL;
+	}
+}
+EXPORT_SYMBOL(sbusfb_ioctl_helper);
+
+#ifdef CONFIG_COMPAT
+int sbusfb_compat_ioctl(struct fb_info *info, unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+	case FBIOGTYPE:
+	case FBIOSATTR:
+	case FBIOGATTR:
+	case FBIOSVIDEO:
+	case FBIOGVIDEO:
+	case FBIOSCURSOR32:
+	case FBIOGCURSOR32:	/* This is not implemented yet.
+				   Later it should be converted... */
+	case FBIOSCURPOS:
+	case FBIOGCURPOS:
+	case FBIOGCURMAX:
+		return info->fbops->fb_ioctl(info, cmd, arg);
+	case FBIOPUTCMAP32:
+	case FBIOPUTCMAP_SPARC: {
+		struct fbcmap32 c;
+		struct fb_cmap cmap;
+		u16 red, green, blue;
+		u8 red8, green8, blue8;
+		unsigned char __user *ured;
+		unsigned char __user *ugreen;
+		unsigned char __user *ublue;
+		unsigned int i;
+
+		if (copy_from_user(&c, compat_ptr(arg), sizeof(c)))
+			return -EFAULT;
+		ured = compat_ptr(c.red);
+		ugreen = compat_ptr(c.green);
+		ublue = compat_ptr(c.blue);
+
+		cmap.len = 1;
+		cmap.red = &red;
+		cmap.green = &green;
+		cmap.blue = &blue;
+		cmap.transp = NULL;
+		for (i = 0; i < c.count; i++) {
+			int err;
+
+			if (get_user(red8, &ured[i]) ||
+			    get_user(green8, &ugreen[i]) ||
+			    get_user(blue8, &ublue[i]))
+				return -EFAULT;
+
+			red = red8 << 8;
+			green = green8 << 8;
+			blue = blue8 << 8;
+
+			cmap.start = c.index + i;
+			err = fb_set_cmap(&cmap, info);
+			if (err)
+				return err;
+		}
+		return 0;
+	}
+	case FBIOGETCMAP32: {
+		struct fbcmap32 c;
+		unsigned char __user *ured;
+		unsigned char __user *ugreen;
+		unsigned char __user *ublue;
+		struct fb_cmap *cmap = &info->cmap;
+		unsigned int index, i;
+		u8 red, green, blue;
+
+		if (copy_from_user(&c, compat_ptr(arg), sizeof(c)))
+			return -EFAULT;
+		index = c.index;
+		ured = compat_ptr(c.red);
+		ugreen = compat_ptr(c.green);
+		ublue = compat_ptr(c.blue);
+
+		if (index > cmap->len || c.count > cmap->len - index)
+			return -EINVAL;
+
+		for (i = 0; i < c.count; i++) {
+			red = cmap->red[index + i] >> 8;
+			green = cmap->green[index + i] >> 8;
+			blue = cmap->blue[index + i] >> 8;
+			if (put_user(red, &ured[i]) ||
+			    put_user(green, &ugreen[i]) ||
+			    put_user(blue, &ublue[i]))
+				return -EFAULT;
+		}
+		return 0;
+	}
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+EXPORT_SYMBOL(sbusfb_compat_ioctl);
+#endif