Re: [PATCH v2] drivers/misc/vmw_vmci: restrict too big queue size in

2021-02-09 Thread Greg KH 
On Tue, Feb 09, 2021 at 03:31:01PM +0600, Sabyrzhan Tasbolatov wrote:
> syzbot found WARNING in qp_broker_alloc[1] in qp_host_alloc_queue()
> when num_pages is 0x11, 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=0x40.
> 
> Reported-by: syzbot+15ec7391f3d6a1a7c...@syzkaller.appspotmail.com
> Signed-off-by: Sabyrzhan Tasbolatov 
> ---
> >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;
> - }
>  

This patch doesn't apply to the tree, you can't send me a patch that is
relative to your previous one, that doesn't work at all.

And also, test-build your patches always first, to not do so is a bit
rude to maintainers...

thanks,

greg k-h

Re: [PATCH v2] drivers/misc/vmw_vmci: restrict too big queue size in

2021-02-09 Thread Alex Dewar 

On 09/02/2021 09:31, Sabyrzhan Tasbolatov wrote:

syzbot found WARNING in qp_broker_alloc[1] in qp_host_alloc_queue()
when num_pages is 0x11, 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=0x40.

Reported-by: syzbot+15ec7391f3d6a1a7c...@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov 
---

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().

Looks like you forgot to take out the opening brace.



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) {

[PATCH v2] drivers/misc/vmw_vmci: restrict too big queue size in

2021-02-09 Thread Sabyrzhan Tasbolatov 
syzbot found WARNING in qp_broker_alloc[1] in qp_host_alloc_queue()
when num_pages is 0x11, 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=0x40.

Reported-by: syzbot+15ec7391f3d6a1a7c...@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov 
---
>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