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Commit fb2c4452 authored by Martijn Coenen's avatar Martijn Coenen Committed by Greg Kroah-Hartman
Browse files

ANDROID: binder: fix transaction leak. 



If a call to put_user() fails, we failed to
properly free a transaction and send a failed
reply (if necessary).

Signed-off-by: default avatarMartijn Coenen <maco@android.com>
Cc: stable <stable@vger.kernel.org> # 4.14
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4fbd8d19

drivers/android/binder.c

+31 −9
Original line number Diff line number Diff line
@@ -1947,6 +1947,26 @@ static void binder_send_failed_reply(struct binder_transaction *t, 
	}

}



/**

 * binder_cleanup_transaction() - cleans up undelivered transaction

 * @t:		transaction that needs to be cleaned up

 * @reason:	reason the transaction wasn't delivered

 * @error_code:	error to return to caller (if synchronous call)

 */

static void binder_cleanup_transaction(struct binder_transaction *t,

				       const char *reason,

				       uint32_t error_code)

{

	if (t->buffer->target_node && !(t->flags & TF_ONE_WAY)) {

		binder_send_failed_reply(t, error_code);

	} else {

		binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,

			"undelivered transaction %d, %s\n",

			t->debug_id, reason);

		binder_free_transaction(t);

	}

}



/**

 * binder_validate_object() - checks for a valid metadata object in a buffer.

 * @buffer:	binder_buffer that we're parsing.
@@ -4015,12 +4035,20 @@ static int binder_thread_read(struct binder_proc *proc, 
		if (put_user(cmd, (uint32_t __user *)ptr)) {

			if (t_from)

				binder_thread_dec_tmpref(t_from);



			binder_cleanup_transaction(t, "put_user failed",

						   BR_FAILED_REPLY);



			return -EFAULT;

		}

		ptr += sizeof(uint32_t);

		if (copy_to_user(ptr, &tr, sizeof(tr))) {

			if (t_from)

				binder_thread_dec_tmpref(t_from);



			binder_cleanup_transaction(t, "copy_to_user failed",

						   BR_FAILED_REPLY);



			return -EFAULT;

		}

		ptr += sizeof(tr);
@@ -4090,15 +4118,9 @@ static void binder_release_work(struct binder_proc *proc, 
			struct binder_transaction *t;



			t = container_of(w, struct binder_transaction, work);

			if (t->buffer->target_node &&

			    !(t->flags & TF_ONE_WAY)) {

				binder_send_failed_reply(t, BR_DEAD_REPLY);

			} else {

				binder_debug(BINDER_DEBUG_DEAD_TRANSACTION,

					"undelivered transaction %d\n",

					t->debug_id);

				binder_free_transaction(t);

			}



			binder_cleanup_transaction(t, "process died.",

						   BR_DEAD_REPLY);

		} break;

		case BINDER_WORK_RETURN_ERROR: {

			struct binder_error *e = container_of(