[PATCH v2] drivers/misc/vmw_vmci: restrict too big queue size in
From: Sabyrzhan Tasbolatov
Date: Tue Feb 09 2021 - 04:34:50 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.
Reported-by: syzbot+15ec7391f3d6a1a7cc7d@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
---
>As this is controllable by userspace, you just provided a way to flood
>the kernel logs.
>
>Please make this a dev_dbg() call instead, if you really want to see it.
>Otherwise just return NULL, no need to report anything, right?
Thanks, removed pr_warn().
v2: Removed pr_warn() to avoid flood from user-space
---
drivers/misc/vmw_vmci/vmci_queue_pair.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c
index f6af406fda80..ea16df73cde0 100644
--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -538,9 +538,7 @@ 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) {
- pr_warn("too big queue to allocate\n");
return NULL;
- }
queue = kzalloc(queue_size + queue_page_size, GFP_KERNEL);
if (queue) {
--
2.25.1