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authorDanilo Krummrich <dakr@redhat.com>2024-07-08 22:07:21 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-10 09:35:09 +0200
commita23b018c3bf646274f02edd46bf448c20c826d94 (patch)
tree21624acc0d86941a19ca26eb057a4ba4739fd10d /rust
parentfirmware_loader: annotate doctests as `no_run` (diff)
downloadlinux-a23b018c3bf646274f02edd46bf448c20c826d94.tar.xz
linux-a23b018c3bf646274f02edd46bf448c20c826d94.zip
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@garyguo.net> Closes: https://lore.kernel.org/lkml/20240620143611.7995e0bb@eugeo/ Signed-off-by: Danilo Krummrich <dakr@redhat.com> Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com> Link: https://lore.kernel.org/r/20240708200724.3203-2-dakr@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'rust')
-rw-r--r--rust/kernel/firmware.rs27
1 files 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 @@ impl Firmware {
// 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 @@ impl Firmware {
/// 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 {