[PATCH v2] binder: fix max_thread type inconsistency

[PATCH v2] binder: fix max_thread type inconsistency

[Carlos Llamas]

The type defined for the BINDER_SET_MAX_THREADS ioctl was changed from
size_t to __u32 in order to avoid incompatibility issues between 32 and
64-bit kernels. However, the internal types used to copy from user and
store the value were never updated. Use u32 to fix the inconsistency.

Fixes: a9350fc859ae ("staging: android: binder: fix BINDER_SET_MAX_THREADS declaration")
Reported-by: Arve Hjønnevåg <arve@android.com>
Cc:  <stable@vger.kernel.org>
Signed-off-by: Carlos Llamas <cmllamas@google.com>
---

Notes:
    v2: rebased, send fix patch separately per Greg's feedback.

 drivers/android/binder.c          | 2 +-
 drivers/android/binder_internal.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index bad28cf42010..5834e829f391 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -5365,7 +5365,7 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			goto err;
 		break;
 	case BINDER_SET_MAX_THREADS: {
-		int max_threads;
+		u32 max_threads;
 
 		if (copy_from_user(&max_threads, ubuf,
 				   sizeof(max_threads))) {
diff --git a/drivers/android/binder_internal.h b/drivers/android/binder_internal.h
index 7270d4d22207..5b7c80b99ae8 100644
--- a/drivers/android/binder_internal.h
+++ b/drivers/android/binder_internal.h
@@ -421,7 +421,7 @@ struct binder_proc {
 	struct list_head todo;
 	struct binder_stats stats;
 	struct list_head delivered_death;
-	int max_threads;
+	u32 max_threads;
 	int requested_threads;
 	int requested_threads_started;
 	int tmp_ref;
-- 
2.44.0.769.g3c40516874-goog

Re: [PATCH v2] binder: fix max_thread type inconsistency

[Alice Ryhl]

On Sun, Apr 21, 2024 at 7:44 PM Carlos Llamas <cmllamas@google.com> wrote:
>
> The type defined for the BINDER_SET_MAX_THREADS ioctl was changed from
> size_t to __u32 in order to avoid incompatibility issues between 32 and
> 64-bit kernels. However, the internal types used to copy from user and
> store the value were never updated. Use u32 to fix the inconsistency.
>
> Fixes: a9350fc859ae ("staging: android: binder: fix BINDER_SET_MAX_THREADS declaration")
> Reported-by: Arve Hjønnevåg <arve@android.com>
> Cc:  <stable@vger.kernel.org>
> Signed-off-by: Carlos Llamas <cmllamas@google.com>

Reviewed-by: Alice Ryhl <aliceryhl@google.com>