[PATCH 4.14 145/176] drivers/misc/vmw_vmci: restrict too big queue size in qp_host_alloc_queue

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 14:25:33 EST


From: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>

commit 2fd10bcf0310b9525b2af9e1f7aa9ddd87c3772e upstream.

syzbot found WARNING in qp_broker_alloc[1] in qp_host_alloc_queue()
when num_pages is 0x100001, giving queue_size + queue_page_size
bigger than KMALLOC_MAX_SIZE for kzalloc(), resulting order >= MAX_ORDER
condition.

queue_size + queue_page_size=0x8000d8, where KMALLOC_MAX_SIZE=0x400000.

[1]
Call Trace:
alloc_pages include/linux/gfp.h:547 [inline]
kmalloc_order+0x40/0x130 mm/slab_common.c:837
kmalloc_order_trace+0x15/0x70 mm/slab_common.c:853
kmalloc_large include/linux/slab.h:481 [inline]
__kmalloc+0x257/0x330 mm/slub.c:3959
kmalloc include/linux/slab.h:557 [inline]
kzalloc include/linux/slab.h:682 [inline]
qp_host_alloc_queue drivers/misc/vmw_vmci/vmci_queue_pair.c:540 [inline]
qp_broker_create drivers/misc/vmw_vmci/vmci_queue_pair.c:1351 [inline]
qp_broker_alloc+0x936/0x2740 drivers/misc/vmw_vmci/vmci_queue_pair.c:1739

Reported-by: syzbot+15ec7391f3d6a1a7cc7d@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
Link: https://lore.kernel.org/r/20210209102612.2112247-1-snovitoll@xxxxxxxxx
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/vmw_vmci/vmci_queue_pair.c | 3 +++
1 file changed, 3 insertions(+)

--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -639,6 +639,9 @@ static struct vmci_queue *qp_host_alloc_

queue_page_size = num_pages * sizeof(*queue->kernel_if->u.h.page);

+ if (queue_size + queue_page_size > KMALLOC_MAX_SIZE)
+ return NULL;
+
queue = kzalloc(queue_size + queue_page_size, GFP_KERNEL);
if (queue) {
queue->q_header = NULL;