From 78004e9a87f240df03e2f73120d291763c32e0a7 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Fri, 21 Aug 2026 01:45:27 +0000 Subject: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [shorne@gmail.com: fix comment style] Fixes: 9d02a4283e9c ("OpenRISC: Boot code") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis Signed-off-by: Stafford Horne --- rust/syn/file.rs | 127 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 rust/syn/file.rs (limited to 'rust/syn/file.rs') 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, + pub attrs: Vec, + pub items: Vec, + } +} + +#[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 { + 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); + } + } +} -- cgit v1.3.1