[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20240708200724.3203-2-dakr@redhat.com>
Date: Mon, 8 Jul 2024 22:07:21 +0200
From: Danilo Krummrich <dakr@...hat.com>
To: mcgrof@...nel.org,
russ.weight@...ux.dev,
gregkh@...uxfoundation.org
Cc: chrisi.schrefl@...il.com,
linux-kernel@...r.kernel.org,
rust-for-linux@...r.kernel.org,
Danilo Krummrich <dakr@...hat.com>,
Gary Guo <gary@...yguo.net>
Subject: [PATCH v2 2/2] firmware_loader: fix soundness issue in `request_internal`
`request_internal` must be called with one of the following function
pointers: request_firmware(), firmware_request_nowarn(),
firmware_request_platform() or request_firmware_direct().
The previous `FwFunc` alias did not guarantee this, which is unsound.
In order to fix this up, implement `FwFunc` as new type with a
corresponding type invariant.
Reported-by: Gary Guo <gary@...yguo.net>
Closes: https://lore.kernel.org/lkml/20240620143611.7995e0bb@eugeo/
Signed-off-by: Danilo Krummrich <dakr@...hat.com>
---
v2:
- provide method for each wrapped `FwFunc` (Christian)
---
rust/kernel/firmware.rs | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs
index 106a928a535e..2ba03af9f036 100644
--- a/rust/kernel/firmware.rs
+++ b/rust/kernel/firmware.rs
@@ -7,10 +7,23 @@
use crate::{bindings, device::Device, error::Error, error::Result, str::CStr};
use core::ptr::NonNull;
-// One of the following: `bindings::request_firmware`, `bindings::firmware_request_nowarn`,
-// `firmware_request_platform`, `bindings::request_firmware_direct`
-type FwFunc =
- unsafe extern "C" fn(*mut *const bindings::firmware, *const i8, *mut bindings::device) -> i32;
+/// # Invariants
+///
+/// One of the following: `bindings::request_firmware`, `bindings::firmware_request_nowarn`,
+/// `bindings::firmware_request_platform`, `bindings::request_firmware_direct`.
+struct FwFunc(
+ unsafe extern "C" fn(*mut *const bindings::firmware, *const i8, *mut bindings::device) -> i32,
+);
+
+impl FwFunc {
+ fn request() -> Self {
+ Self(bindings::request_firmware)
+ }
+
+ fn request_nowarn() -> Self {
+ Self(bindings::firmware_request_nowarn)
+ }
+}
/// Abstraction around a C `struct firmware`.
///
@@ -48,7 +61,7 @@ fn request_internal(name: &CStr, dev: &Device, func: FwFunc) -> Result<Self> {
// SAFETY: `pfw` is a valid pointer to a NULL initialized `bindings::firmware` pointer.
// `name` and `dev` are valid as by their type invariants.
- let ret = unsafe { func(pfw as _, name.as_char_ptr(), dev.as_raw()) };
+ let ret = unsafe { func.0(pfw as _, name.as_char_ptr(), dev.as_raw()) };
if ret != 0 {
return Err(Error::from_errno(ret));
}
@@ -60,13 +73,13 @@ fn request_internal(name: &CStr, dev: &Device, func: FwFunc) -> Result<Self> {
/// Send a firmware request and wait for it. See also `bindings::request_firmware`.
pub fn request(name: &CStr, dev: &Device) -> Result<Self> {
- Self::request_internal(name, dev, bindings::request_firmware)
+ Self::request_internal(name, dev, FwFunc::request())
}
/// Send a request for an optional firmware module. See also
/// `bindings::firmware_request_nowarn`.
pub fn request_nowarn(name: &CStr, dev: &Device) -> Result<Self> {
- Self::request_internal(name, dev, bindings::firmware_request_nowarn)
+ Self::request_internal(name, dev, FwFunc::request_nowarn())
}
fn as_raw(&self) -> *mut bindings::firmware {
--
2.45.2
Powered by blists - more mailing lists