rust_binder: avoid mem::take on delivered_deaths

Similar to the previous commit, List::remove is used on
delivered_deaths, so do not use mem::take on it as that may result in
violations of the List::remove safety requirements.

I don't think this particular case can be triggered because it requires
fd close to run in parallel with an ioctl on the same fd. But let's not
tempt fate.

Cc: stable@vger.kernel.org
Fixes: eafedbc7c050 ("rust_binder: add Rust Binder driver")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://patch.msgid.link/20251111-binder-fix-list-remove-v1-2-8ed14a0da63d@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/android/binder/process.rs b/drivers/android/binder/process.rs
index 27323070f30f16ea3ccd8b6a2d032617c1ac1e4a..fd5dcdc8788ccb0a098b2f4947c66c56c854304f 100644 (file)
--- a/drivers/android/binder/process.rs
+++ b/drivers/android/binder/process.rs
@@ -1362,8 +1362,12 @@ impl Process {
             work.into_arc().cancel();
         }
 
-        let delivered_deaths = take(&mut self.inner.lock().delivered_deaths);
-        drop(delivered_deaths);
+        // Clear delivered_deaths list.
+        //
+        // Scope ensures that MutexGuard is dropped while executing the body.
+        while let Some(delivered_death) = { self.inner.lock().delivered_deaths.pop_front() } {
+            drop(delivered_death);
+        }
 
         // Free any resources kept alive by allocated buffers.
         let omapping = self.inner.lock().mapping.take();