[PATCH v4] drivers/misc/vmw_vmci: restrict too big queue size in qp_host_alloc_queue

From: Sabyrzhan Tasbolatov
Date: Tue Feb 09 2021 - 05:32:54 EST


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>
---
> This patch does not apply to the tree...
Apologies, it was so stupid from my side.
Tested locally and via syzbot.

v4: made a patch based on commit 65f0d2414b("Merge tag 'sound-5.11-rc4'
of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound")
---
drivers/misc/vmw_vmci/vmci_queue_pair.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index c49065887e8f..024dcdbd9d01 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -537,6 +537,9 @@ static struct vmci_queue *qp_host_alloc_queue(u64 size)

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;
--
2.25.1