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, 127 insertions, 0 deletions

diff --git a/rust/syn/file.rs b/rust/syn/file.rs
new file mode 100644
index 000000000..ce2d2680c
--- /dev/null
+++ b/rust/syn/file.rs
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+use crate::attr::Attribute;
+use crate::item::Item;
+
+ast_struct! {
+    /// A complete file of Rust source code.
+    ///
+    /// Typically `File` objects are created with [`parse_file`].
+    ///
+    /// [`parse_file`]: crate::parse_file
+    ///
+    /// # Example
+    ///
+    /// Parse a Rust source file into a `syn::File` and print out a debug
+    /// representation of the syntax tree.
+    ///
+    /// ```
+    /// use std::env;
+    /// use std::fs;
+    /// use std::process;
+    ///
+    /// fn main() {
+    /// # }
+    /// #
+    /// # fn fake_main() {
+    ///     let mut args = env::args();
+    ///     let _ = args.next(); // executable name
+    ///
+    ///     let filename = match (args.next(), args.next()) {
+    ///         (Some(filename), None) => filename,
+    ///         _ => {
+    ///             eprintln!("Usage: dump-syntax path/to/filename.rs");
+    ///             process::exit(1);
+    ///         }
+    ///     };
+    ///
+    ///     let src = fs::read_to_string(&filename).expect("unable to read file");
+    ///     let syntax = syn::parse_file(&src).expect("unable to parse file");
+    ///
+    ///     // Debug impl is available if Syn is built with "extra-traits" feature.
+    ///     println!("{:#?}", syntax);
+    /// }
+    /// ```
+    ///
+    /// Running with its own source code as input, this program prints output
+    /// that begins with:
+    ///
+    /// ```text
+    /// File {
+    ///     shebang: None,
+    ///     attrs: [],
+    ///     items: [
+    ///         Use(
+    ///             ItemUse {
+    ///                 attrs: [],
+    ///                 vis: Inherited,
+    ///                 use_token: Use,
+    ///                 leading_colon: None,
+    ///                 tree: Path(
+    ///                     UsePath {
+    ///                         ident: Ident(
+    ///                             std,
+    ///                         ),
+    ///                         colon2_token: Colon2,
+    ///                         tree: Name(
+    ///                             UseName {
+    ///                                 ident: Ident(
+    ///                                     env,
+    ///                                 ),
+    ///                             },
+    ///                         ),
+    ///                     },
+    ///                 ),
+    ///                 semi_token: Semi,
+    ///             },
+    ///         ),
+    /// ...
+    /// ```
+    #[cfg_attr(docsrs, doc(cfg(feature = "full")))]
+    pub struct File {
+        pub shebang: Option<String>,
+        pub attrs: Vec<Attribute>,
+        pub items: Vec<Item>,
+    }
+}
+
+#[cfg(feature = "parsing")]
+pub(crate) mod parsing {
+    use crate::attr::Attribute;
+    use crate::error::Result;
+    use crate::file::File;
+    use crate::parse::{Parse, ParseStream};
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "parsing")))]
+    impl Parse for File {
+        fn parse(input: ParseStream) -> Result<Self> {
+            Ok(File {
+                shebang: None,
+                attrs: input.call(Attribute::parse_inner)?,
+                items: {
+                    let mut items = Vec::new();
+                    while !input.is_empty() {
+                        items.push(input.parse()?);
+                    }
+                    items
+                },
+            })
+        }
+    }
+}
+
+#[cfg(feature = "printing")]
+mod printing {
+    use crate::attr::FilterAttrs;
+    use crate::file::File;
+    use proc_macro2::TokenStream;
+    use quote::{ToTokens, TokenStreamExt};
+
+    #[cfg_attr(docsrs, doc(cfg(feature = "printing")))]
+    impl ToTokens for File {
+        fn to_tokens(&self, tokens: &mut TokenStream) {
+            tokens.append_all(self.attrs.inner());
+            tokens.append_all(&self.items);
+        }
+    }
+}