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, 159 insertions, 0 deletions

diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
new file mode 100644
index 000000000..c3fea55b8
--- /dev/null
+++ b/fs/ext2/ioctl.c
@@ -0,0 +1,159 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/ext2/ioctl.c
+ *
+ * Copyright (C) 1993, 1994, 1995
+ * Remy Card (card@masi.ibp.fr)
+ * Laboratoire MASI - Institut Blaise Pascal
+ * Universite Pierre et Marie Curie (Paris VI)
+ */
+
+#include "ext2.h"
+#include <linux/capability.h>
+#include <linux/time.h>
+#include <linux/sched.h>
+#include <linux/compat.h>
+#include <linux/mount.h>
+#include <asm/current.h>
+#include <linux/uaccess.h>
+#include <linux/fileattr.h>
+
+int ext2_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct ext2_inode_info *ei = EXT2_I(d_inode(dentry));
+
+	fileattr_fill_flags(fa, ei->i_flags & EXT2_FL_USER_VISIBLE);
+
+	return 0;
+}
+
+int ext2_fileattr_set(struct mnt_idmap *idmap,
+		      struct dentry *dentry, struct file_kattr *fa)
+{
+	struct inode *inode = d_inode(dentry);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+
+	if (fileattr_has_fsx(fa))
+		return -EOPNOTSUPP;
+
+	/* Is it quota file? Do not allow user to mess with it */
+	if (IS_NOQUOTA(inode))
+		return -EPERM;
+
+	ei->i_flags = (ei->i_flags & ~EXT2_FL_USER_MODIFIABLE) |
+		(fa->flags & EXT2_FL_USER_MODIFIABLE);
+
+	ext2_set_inode_flags(inode);
+	inode_set_ctime_current(inode);
+	mark_inode_dirty(inode);
+
+	return 0;
+}
+
+
+long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
+{
+	struct inode *inode = file_inode(filp);
+	struct ext2_inode_info *ei = EXT2_I(inode);
+	unsigned short rsv_window_size;
+	int ret;
+
+	ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
+
+	switch (cmd) {
+	case EXT2_IOC_GETVERSION:
+		return put_user(inode->i_generation, (int __user *) arg);
+	case EXT2_IOC_SETVERSION: {
+		__u32 generation;
+
+		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
+			return -EPERM;
+		ret = mnt_want_write_file(filp);
+		if (ret)
+			return ret;
+		if (get_user(generation, (int __user *) arg)) {
+			ret = -EFAULT;
+			goto setversion_out;
+		}
+
+		inode_lock(inode);
+		inode_set_ctime_current(inode);
+		inode->i_generation = generation;
+		inode_unlock(inode);
+
+		mark_inode_dirty(inode);
+setversion_out:
+		mnt_drop_write_file(filp);
+		return ret;
+	}
+	case EXT2_IOC_GETRSVSZ:
+		if (test_opt(inode->i_sb, RESERVATION)
+			&& S_ISREG(inode->i_mode)
+			&& ei->i_block_alloc_info) {
+			rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
+			return put_user(rsv_window_size, (int __user *)arg);
+		}
+		return -ENOTTY;
+	case EXT2_IOC_SETRSVSZ: {
+
+		if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
+			return -ENOTTY;
+
+		if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
+			return -EACCES;
+
+		if (get_user(rsv_window_size, (int __user *)arg))
+			return -EFAULT;
+
+		ret = mnt_want_write_file(filp);
+		if (ret)
+			return ret;
+
+		if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
+			rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
+
+		/*
+		 * need to allocate reservation structure for this inode
+		 * before set the window size
+		 */
+		/*
+		 * XXX What lock should protect the rsv_goal_size?
+		 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
+		 */
+		mutex_lock(&ei->truncate_mutex);
+		if (!ei->i_block_alloc_info)
+			ext2_init_block_alloc_info(inode);
+
+		if (ei->i_block_alloc_info){
+			struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
+			rsv->rsv_goal_size = rsv_window_size;
+		} else {
+			ret = -ENOMEM;
+		}
+
+		mutex_unlock(&ei->truncate_mutex);
+		mnt_drop_write_file(filp);
+		return ret;
+	}
+	default:
+		return -ENOTTY;
+	}
+}
+
+#ifdef CONFIG_COMPAT
+long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	/* These are just misnamed, they actually get/put from/to user an int */
+	switch (cmd) {
+	case EXT2_IOC32_GETVERSION:
+		cmd = EXT2_IOC_GETVERSION;
+		break;
+	case EXT2_IOC32_SETVERSION:
+		cmd = EXT2_IOC_SETVERSION;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
+}
+#endif