Update Linux to v5.10.157

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.157.tar.xz

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I7b30d9e98d8c465d6b44de8e7433b4a40b3289ba
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 366b124..4473ade 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -1744,6 +1744,18 @@
 	}
 	ret = binder_inc_ref_olocked(ref, strong, target_list);
 	*rdata = ref->data;
+	if (ret && ref == new_ref) {
+		/*
+		 * Cleanup the failed reference here as the target
+		 * could now be dead and have already released its
+		 * references by now. Calling on the new reference
+		 * with strong=0 and a tmp_refs will not decrement
+		 * the node. The new_ref gets kfree'd below.
+		 */
+		binder_cleanup_ref_olocked(new_ref);
+		ref = NULL;
+	}
+
 	binder_proc_unlock(proc);
 	if (new_ref && ref != new_ref)
 		/*
@@ -1996,15 +2008,21 @@
 /**
  * binder_get_object() - gets object and checks for valid metadata
  * @proc:	binder_proc owning the buffer
+ * @u:		sender's user pointer to base of buffer
  * @buffer:	binder_buffer that we're parsing.
  * @offset:	offset in the @buffer at which to validate an object.
  * @object:	struct binder_object to read into
  *
- * Return:	If there's a valid metadata object at @offset in @buffer, the
+ * Copy the binder object at the given offset into @object. If @u is
+ * provided then the copy is from the sender's buffer. If not, then
+ * it is copied from the target's @buffer.
+ *
+ * Return:	If there's a valid metadata object at @offset, the
  *		size of that object. Otherwise, it returns zero. The object
  *		is read into the struct binder_object pointed to by @object.
  */
 static size_t binder_get_object(struct binder_proc *proc,
+				const void __user *u,
 				struct binder_buffer *buffer,
 				unsigned long offset,
 				struct binder_object *object)
@@ -2014,10 +2032,16 @@
 	size_t object_size = 0;
 
 	read_size = min_t(size_t, sizeof(*object), buffer->data_size - offset);
-	if (offset > buffer->data_size || read_size < sizeof(*hdr) ||
-	    binder_alloc_copy_from_buffer(&proc->alloc, object, buffer,
-					  offset, read_size))
+	if (offset > buffer->data_size || read_size < sizeof(*hdr))
 		return 0;
+	if (u) {
+		if (copy_from_user(object, u + offset, read_size))
+			return 0;
+	} else {
+		if (binder_alloc_copy_from_buffer(&proc->alloc, object, buffer,
+						  offset, read_size))
+			return 0;
+	}
 
 	/* Ok, now see if we read a complete object. */
 	hdr = &object->hdr;
@@ -2090,7 +2114,7 @@
 					  b, buffer_offset,
 					  sizeof(object_offset)))
 		return NULL;
-	object_size = binder_get_object(proc, b, object_offset, object);
+	object_size = binder_get_object(proc, NULL, b, object_offset, object);
 	if (!object_size || object->hdr.type != BINDER_TYPE_PTR)
 		return NULL;
 	if (object_offsetp)
@@ -2155,7 +2179,8 @@
 		unsigned long buffer_offset;
 		struct binder_object last_object;
 		struct binder_buffer_object *last_bbo;
-		size_t object_size = binder_get_object(proc, b, last_obj_offset,
+		size_t object_size = binder_get_object(proc, NULL, b,
+						       last_obj_offset,
 						       &last_object);
 		if (object_size != sizeof(*last_bbo))
 			return false;
@@ -2270,7 +2295,7 @@
 		if (!binder_alloc_copy_from_buffer(&proc->alloc, &object_offset,
 						   buffer, buffer_offset,
 						   sizeof(object_offset)))
-			object_size = binder_get_object(proc, buffer,
+			object_size = binder_get_object(proc, NULL, buffer,
 							object_offset, &object);
 		if (object_size == 0) {
 			pr_err("transaction release %d bad object at offset %lld, size %zd\n",
@@ -2608,16 +2633,266 @@
 	return ret;
 }
 
-static int binder_translate_fd_array(struct binder_fd_array_object *fda,
+/**
+ * struct binder_ptr_fixup - data to be fixed-up in target buffer
+ * @offset	offset in target buffer to fixup
+ * @skip_size	bytes to skip in copy (fixup will be written later)
+ * @fixup_data	data to write at fixup offset
+ * @node	list node
+ *
+ * This is used for the pointer fixup list (pf) which is created and consumed
+ * during binder_transaction() and is only accessed locally. No
+ * locking is necessary.
+ *
+ * The list is ordered by @offset.
+ */
+struct binder_ptr_fixup {
+	binder_size_t offset;
+	size_t skip_size;
+	binder_uintptr_t fixup_data;
+	struct list_head node;
+};
+
+/**
+ * struct binder_sg_copy - scatter-gather data to be copied
+ * @offset		offset in target buffer
+ * @sender_uaddr	user address in source buffer
+ * @length		bytes to copy
+ * @node		list node
+ *
+ * This is used for the sg copy list (sgc) which is created and consumed
+ * during binder_transaction() and is only accessed locally. No
+ * locking is necessary.
+ *
+ * The list is ordered by @offset.
+ */
+struct binder_sg_copy {
+	binder_size_t offset;
+	const void __user *sender_uaddr;
+	size_t length;
+	struct list_head node;
+};
+
+/**
+ * binder_do_deferred_txn_copies() - copy and fixup scatter-gather data
+ * @alloc:	binder_alloc associated with @buffer
+ * @buffer:	binder buffer in target process
+ * @sgc_head:	list_head of scatter-gather copy list
+ * @pf_head:	list_head of pointer fixup list
+ *
+ * Processes all elements of @sgc_head, applying fixups from @pf_head
+ * and copying the scatter-gather data from the source process' user
+ * buffer to the target's buffer. It is expected that the list creation
+ * and processing all occurs during binder_transaction() so these lists
+ * are only accessed in local context.
+ *
+ * Return: 0=success, else -errno
+ */
+static int binder_do_deferred_txn_copies(struct binder_alloc *alloc,
+					 struct binder_buffer *buffer,
+					 struct list_head *sgc_head,
+					 struct list_head *pf_head)
+{
+	int ret = 0;
+	struct binder_sg_copy *sgc, *tmpsgc;
+	struct binder_ptr_fixup *tmppf;
+	struct binder_ptr_fixup *pf =
+		list_first_entry_or_null(pf_head, struct binder_ptr_fixup,
+					 node);
+
+	list_for_each_entry_safe(sgc, tmpsgc, sgc_head, node) {
+		size_t bytes_copied = 0;
+
+		while (bytes_copied < sgc->length) {
+			size_t copy_size;
+			size_t bytes_left = sgc->length - bytes_copied;
+			size_t offset = sgc->offset + bytes_copied;
+
+			/*
+			 * We copy up to the fixup (pointed to by pf)
+			 */
+			copy_size = pf ? min(bytes_left, (size_t)pf->offset - offset)
+				       : bytes_left;
+			if (!ret && copy_size)
+				ret = binder_alloc_copy_user_to_buffer(
+						alloc, buffer,
+						offset,
+						sgc->sender_uaddr + bytes_copied,
+						copy_size);
+			bytes_copied += copy_size;
+			if (copy_size != bytes_left) {
+				BUG_ON(!pf);
+				/* we stopped at a fixup offset */
+				if (pf->skip_size) {
+					/*
+					 * we are just skipping. This is for
+					 * BINDER_TYPE_FDA where the translated
+					 * fds will be fixed up when we get
+					 * to target context.
+					 */
+					bytes_copied += pf->skip_size;
+				} else {
+					/* apply the fixup indicated by pf */
+					if (!ret)
+						ret = binder_alloc_copy_to_buffer(
+							alloc, buffer,
+							pf->offset,
+							&pf->fixup_data,
+							sizeof(pf->fixup_data));
+					bytes_copied += sizeof(pf->fixup_data);
+				}
+				list_del(&pf->node);
+				kfree(pf);
+				pf = list_first_entry_or_null(pf_head,
+						struct binder_ptr_fixup, node);
+			}
+		}
+		list_del(&sgc->node);
+		kfree(sgc);
+	}
+	list_for_each_entry_safe(pf, tmppf, pf_head, node) {
+		BUG_ON(pf->skip_size == 0);
+		list_del(&pf->node);
+		kfree(pf);
+	}
+	BUG_ON(!list_empty(sgc_head));
+
+	return ret > 0 ? -EINVAL : ret;
+}
+
+/**
+ * binder_cleanup_deferred_txn_lists() - free specified lists
+ * @sgc_head:	list_head of scatter-gather copy list
+ * @pf_head:	list_head of pointer fixup list
+ *
+ * Called to clean up @sgc_head and @pf_head if there is an
+ * error.
+ */
+static void binder_cleanup_deferred_txn_lists(struct list_head *sgc_head,
+					      struct list_head *pf_head)
+{
+	struct binder_sg_copy *sgc, *tmpsgc;
+	struct binder_ptr_fixup *pf, *tmppf;
+
+	list_for_each_entry_safe(sgc, tmpsgc, sgc_head, node) {
+		list_del(&sgc->node);
+		kfree(sgc);
+	}
+	list_for_each_entry_safe(pf, tmppf, pf_head, node) {
+		list_del(&pf->node);
+		kfree(pf);
+	}
+}
+
+/**
+ * binder_defer_copy() - queue a scatter-gather buffer for copy
+ * @sgc_head:		list_head of scatter-gather copy list
+ * @offset:		binder buffer offset in target process
+ * @sender_uaddr:	user address in source process
+ * @length:		bytes to copy
+ *
+ * Specify a scatter-gather block to be copied. The actual copy must
+ * be deferred until all the needed fixups are identified and queued.
+ * Then the copy and fixups are done together so un-translated values
+ * from the source are never visible in the target buffer.
+ *
+ * We are guaranteed that repeated calls to this function will have
+ * monotonically increasing @offset values so the list will naturally
+ * be ordered.
+ *
+ * Return: 0=success, else -errno
+ */
+static int binder_defer_copy(struct list_head *sgc_head, binder_size_t offset,
+			     const void __user *sender_uaddr, size_t length)
+{
+	struct binder_sg_copy *bc = kzalloc(sizeof(*bc), GFP_KERNEL);
+
+	if (!bc)
+		return -ENOMEM;
+
+	bc->offset = offset;
+	bc->sender_uaddr = sender_uaddr;
+	bc->length = length;
+	INIT_LIST_HEAD(&bc->node);
+
+	/*
+	 * We are guaranteed that the deferred copies are in-order
+	 * so just add to the tail.
+	 */
+	list_add_tail(&bc->node, sgc_head);
+
+	return 0;
+}
+
+/**
+ * binder_add_fixup() - queue a fixup to be applied to sg copy
+ * @pf_head:	list_head of binder ptr fixup list
+ * @offset:	binder buffer offset in target process
+ * @fixup:	bytes to be copied for fixup
+ * @skip_size:	bytes to skip when copying (fixup will be applied later)
+ *
+ * Add the specified fixup to a list ordered by @offset. When copying
+ * the scatter-gather buffers, the fixup will be copied instead of
+ * data from the source buffer. For BINDER_TYPE_FDA fixups, the fixup
+ * will be applied later (in target process context), so we just skip
+ * the bytes specified by @skip_size. If @skip_size is 0, we copy the
+ * value in @fixup.
+ *
+ * This function is called *mostly* in @offset order, but there are
+ * exceptions. Since out-of-order inserts are relatively uncommon,
+ * we insert the new element by searching backward from the tail of
+ * the list.
+ *
+ * Return: 0=success, else -errno
+ */
+static int binder_add_fixup(struct list_head *pf_head, binder_size_t offset,
+			    binder_uintptr_t fixup, size_t skip_size)
+{
+	struct binder_ptr_fixup *pf = kzalloc(sizeof(*pf), GFP_KERNEL);
+	struct binder_ptr_fixup *tmppf;
+
+	if (!pf)
+		return -ENOMEM;
+
+	pf->offset = offset;
+	pf->fixup_data = fixup;
+	pf->skip_size = skip_size;
+	INIT_LIST_HEAD(&pf->node);
+
+	/* Fixups are *mostly* added in-order, but there are some
+	 * exceptions. Look backwards through list for insertion point.
+	 */
+	list_for_each_entry_reverse(tmppf, pf_head, node) {
+		if (tmppf->offset < pf->offset) {
+			list_add(&pf->node, &tmppf->node);
+			return 0;
+		}
+	}
+	/*
+	 * if we get here, then the new offset is the lowest so
+	 * insert at the head
+	 */
+	list_add(&pf->node, pf_head);
+	return 0;
+}
+
+static int binder_translate_fd_array(struct list_head *pf_head,
+				     struct binder_fd_array_object *fda,
+				     const void __user *sender_ubuffer,
 				     struct binder_buffer_object *parent,
+				     struct binder_buffer_object *sender_uparent,
 				     struct binder_transaction *t,
 				     struct binder_thread *thread,
 				     struct binder_transaction *in_reply_to)
 {
 	binder_size_t fdi, fd_buf_size;
 	binder_size_t fda_offset;
+	const void __user *sender_ufda_base;
 	struct binder_proc *proc = thread->proc;
-	struct binder_proc *target_proc = t->to_proc;
+	int ret;
+
+	if (fda->num_fds == 0)
+		return 0;
 
 	fd_buf_size = sizeof(u32) * fda->num_fds;
 	if (fda->num_fds >= SIZE_MAX / sizeof(u32)) {
@@ -2641,19 +2916,25 @@
 	 */
 	fda_offset = (parent->buffer - (uintptr_t)t->buffer->user_data) +
 		fda->parent_offset;
-	if (!IS_ALIGNED((unsigned long)fda_offset, sizeof(u32))) {
+	sender_ufda_base = (void __user *)(uintptr_t)sender_uparent->buffer +
+				fda->parent_offset;
+
+	if (!IS_ALIGNED((unsigned long)fda_offset, sizeof(u32)) ||
+	    !IS_ALIGNED((unsigned long)sender_ufda_base, sizeof(u32))) {
 		binder_user_error("%d:%d parent offset not aligned correctly.\n",
 				  proc->pid, thread->pid);
 		return -EINVAL;
 	}
+	ret = binder_add_fixup(pf_head, fda_offset, 0, fda->num_fds * sizeof(u32));
+	if (ret)
+		return ret;
+
 	for (fdi = 0; fdi < fda->num_fds; fdi++) {
 		u32 fd;
-		int ret;
 		binder_size_t offset = fda_offset + fdi * sizeof(fd);
+		binder_size_t sender_uoffset = fdi * sizeof(fd);
 
-		ret = binder_alloc_copy_from_buffer(&target_proc->alloc,
-						    &fd, t->buffer,
-						    offset, sizeof(fd));
+		ret = copy_from_user(&fd, sender_ufda_base + sender_uoffset, sizeof(fd));
 		if (!ret)
 			ret = binder_translate_fd(fd, offset, t, thread,
 						  in_reply_to);
@@ -2663,7 +2944,8 @@
 	return 0;
 }
 
-static int binder_fixup_parent(struct binder_transaction *t,
+static int binder_fixup_parent(struct list_head *pf_head,
+			       struct binder_transaction *t,
 			       struct binder_thread *thread,
 			       struct binder_buffer_object *bp,
 			       binder_size_t off_start_offset,
@@ -2709,14 +2991,7 @@
 	}
 	buffer_offset = bp->parent_offset +
 			(uintptr_t)parent->buffer - (uintptr_t)b->user_data;
-	if (binder_alloc_copy_to_buffer(&target_proc->alloc, b, buffer_offset,
-					&bp->buffer, sizeof(bp->buffer))) {
-		binder_user_error("%d:%d got transaction with invalid parent offset\n",
-				  proc->pid, thread->pid);
-		return -EINVAL;
-	}
-
-	return 0;
+	return binder_add_fixup(pf_head, buffer_offset, bp->buffer, 0);
 }
 
 /**
@@ -2836,6 +3111,7 @@
 	binder_size_t off_start_offset, off_end_offset;
 	binder_size_t off_min;
 	binder_size_t sg_buf_offset, sg_buf_end_offset;
+	binder_size_t user_offset = 0;
 	struct binder_proc *target_proc = NULL;
 	struct binder_thread *target_thread = NULL;
 	struct binder_node *target_node = NULL;
@@ -2850,6 +3126,12 @@
 	int t_debug_id = atomic_inc_return(&binder_last_id);
 	char *secctx = NULL;
 	u32 secctx_sz = 0;
+	struct list_head sgc_head;
+	struct list_head pf_head;
+	const void __user *user_buffer = (const void __user *)
+				(uintptr_t)tr->data.ptr.buffer;
+	INIT_LIST_HEAD(&sgc_head);
+	INIT_LIST_HEAD(&pf_head);
 
 	e = binder_transaction_log_add(&binder_transaction_log);
 	e->debug_id = t_debug_id;
@@ -3163,19 +3445,6 @@
 
 	if (binder_alloc_copy_user_to_buffer(
 				&target_proc->alloc,
-				t->buffer, 0,
-				(const void __user *)
-					(uintptr_t)tr->data.ptr.buffer,
-				tr->data_size)) {
-		binder_user_error("%d:%d got transaction with invalid data ptr\n",
-				proc->pid, thread->pid);
-		return_error = BR_FAILED_REPLY;
-		return_error_param = -EFAULT;
-		return_error_line = __LINE__;
-		goto err_copy_data_failed;
-	}
-	if (binder_alloc_copy_user_to_buffer(
-				&target_proc->alloc,
 				t->buffer,
 				ALIGN(tr->data_size, sizeof(void *)),
 				(const void __user *)
@@ -3218,6 +3487,7 @@
 		size_t object_size;
 		struct binder_object object;
 		binder_size_t object_offset;
+		binder_size_t copy_size;
 
 		if (binder_alloc_copy_from_buffer(&target_proc->alloc,
 						  &object_offset,
@@ -3229,8 +3499,27 @@
 			return_error_line = __LINE__;
 			goto err_bad_offset;
 		}
-		object_size = binder_get_object(target_proc, t->buffer,
-						object_offset, &object);
+
+		/*
+		 * Copy the source user buffer up to the next object
+		 * that will be processed.
+		 */
+		copy_size = object_offset - user_offset;
+		if (copy_size && (user_offset > object_offset ||
+				binder_alloc_copy_user_to_buffer(
+					&target_proc->alloc,
+					t->buffer, user_offset,
+					user_buffer + user_offset,
+					copy_size))) {
+			binder_user_error("%d:%d got transaction with invalid data ptr\n",
+					proc->pid, thread->pid);
+			return_error = BR_FAILED_REPLY;
+			return_error_param = -EFAULT;
+			return_error_line = __LINE__;
+			goto err_copy_data_failed;
+		}
+		object_size = binder_get_object(target_proc, user_buffer,
+				t->buffer, object_offset, &object);
 		if (object_size == 0 || object_offset < off_min) {
 			binder_user_error("%d:%d got transaction with invalid offset (%lld, min %lld max %lld) or object.\n",
 					  proc->pid, thread->pid,
@@ -3242,6 +3531,11 @@
 			return_error_line = __LINE__;
 			goto err_bad_offset;
 		}
+		/*
+		 * Set offset to the next buffer fragment to be
+		 * copied
+		 */
+		user_offset = object_offset + object_size;
 
 		hdr = &object.hdr;
 		off_min = object_offset + object_size;
@@ -3304,6 +3598,8 @@
 		case BINDER_TYPE_FDA: {
 			struct binder_object ptr_object;
 			binder_size_t parent_offset;
+			struct binder_object user_object;
+			size_t user_parent_size;
 			struct binder_fd_array_object *fda =
 				to_binder_fd_array_object(hdr);
 			size_t num_valid = (buffer_offset - off_start_offset) /
@@ -3335,11 +3631,35 @@
 				return_error_line = __LINE__;
 				goto err_bad_parent;
 			}
-			ret = binder_translate_fd_array(fda, parent, t, thread,
-							in_reply_to);
-			if (ret < 0) {
+			/*
+			 * We need to read the user version of the parent
+			 * object to get the original user offset
+			 */
+			user_parent_size =
+				binder_get_object(proc, user_buffer, t->buffer,
+						  parent_offset, &user_object);
+			if (user_parent_size != sizeof(user_object.bbo)) {
+				binder_user_error("%d:%d invalid ptr object size: %zd vs %zd\n",
+						  proc->pid, thread->pid,
+						  user_parent_size,
+						  sizeof(user_object.bbo));
 				return_error = BR_FAILED_REPLY;
-				return_error_param = ret;
+				return_error_param = -EINVAL;
+				return_error_line = __LINE__;
+				goto err_bad_parent;
+			}
+			ret = binder_translate_fd_array(&pf_head, fda,
+							user_buffer, parent,
+							&user_object.bbo, t,
+							thread, in_reply_to);
+			if (!ret)
+				ret = binder_alloc_copy_to_buffer(&target_proc->alloc,
+								  t->buffer,
+								  object_offset,
+								  fda, sizeof(*fda));
+			if (ret) {
+				return_error = BR_FAILED_REPLY;
+				return_error_param = ret > 0 ? -EINVAL : ret;
 				return_error_line = __LINE__;
 				goto err_translate_failed;
 			}
@@ -3361,19 +3681,14 @@
 				return_error_line = __LINE__;
 				goto err_bad_offset;
 			}
-			if (binder_alloc_copy_user_to_buffer(
-						&target_proc->alloc,
-						t->buffer,
-						sg_buf_offset,
-						(const void __user *)
-							(uintptr_t)bp->buffer,
-						bp->length)) {
-				binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
-						  proc->pid, thread->pid);
-				return_error_param = -EFAULT;
+			ret = binder_defer_copy(&sgc_head, sg_buf_offset,
+				(const void __user *)(uintptr_t)bp->buffer,
+				bp->length);
+			if (ret) {
 				return_error = BR_FAILED_REPLY;
+				return_error_param = ret;
 				return_error_line = __LINE__;
-				goto err_copy_data_failed;
+				goto err_translate_failed;
 			}
 			/* Fixup buffer pointer to target proc address space */
 			bp->buffer = (uintptr_t)
@@ -3382,7 +3697,8 @@
 
 			num_valid = (buffer_offset - off_start_offset) /
 					sizeof(binder_size_t);
-			ret = binder_fixup_parent(t, thread, bp,
+			ret = binder_fixup_parent(&pf_head, t,
+						  thread, bp,
 						  off_start_offset,
 						  num_valid,
 						  last_fixup_obj_off,
@@ -3409,6 +3725,30 @@
 			goto err_bad_object_type;
 		}
 	}
+	/* Done processing objects, copy the rest of the buffer */
+	if (binder_alloc_copy_user_to_buffer(
+				&target_proc->alloc,
+				t->buffer, user_offset,
+				user_buffer + user_offset,
+				tr->data_size - user_offset)) {
+		binder_user_error("%d:%d got transaction with invalid data ptr\n",
+				proc->pid, thread->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = -EFAULT;
+		return_error_line = __LINE__;
+		goto err_copy_data_failed;
+	}
+
+	ret = binder_do_deferred_txn_copies(&target_proc->alloc, t->buffer,
+					    &sgc_head, &pf_head);
+	if (ret) {
+		binder_user_error("%d:%d got transaction with invalid offsets ptr\n",
+				  proc->pid, thread->pid);
+		return_error = BR_FAILED_REPLY;
+		return_error_param = ret;
+		return_error_line = __LINE__;
+		goto err_copy_data_failed;
+	}
 	tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
 	t->work.type = BINDER_WORK_TRANSACTION;
 
@@ -3475,6 +3815,7 @@
 err_bad_offset:
 err_bad_parent:
 err_copy_data_failed:
+	binder_cleanup_deferred_txn_lists(&sgc_head, &pf_head);
 	binder_free_txn_fixups(t);
 	trace_binder_transaction_failed_buffer_release(t->buffer);
 	binder_transaction_buffer_release(target_proc, NULL, t->buffer,
@@ -6069,6 +6410,7 @@
 	.open = binder_open,
 	.flush = binder_flush,
 	.release = binder_release,
+	.may_pollfree = true,
 };
 
 static int __init init_binder_device(const char *name)
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index 95ca4f9..a77ed66 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -212,7 +212,7 @@
 		mm = alloc->vma_vm_mm;
 
 	if (mm) {
-		mmap_read_lock(mm);
+		mmap_write_lock(mm);
 		vma = alloc->vma;
 	}
 
@@ -270,7 +270,7 @@
 		trace_binder_alloc_page_end(alloc, index);
 	}
 	if (mm) {
-		mmap_read_unlock(mm);
+		mmap_write_unlock(mm);
 		mmput(mm);
 	}
 	return 0;
@@ -303,7 +303,7 @@
 	}
 err_no_vma:
 	if (mm) {
-		mmap_read_unlock(mm);
+		mmap_write_unlock(mm);
 		mmput(mm);
 	}
 	return vma ? -ENOMEM : -ESRCH;