Re: [PATCH v3 net] vsock: fix buffer size clamping order

[Stefano Garzarella]

On Thu, Apr 09, 2026 at 06:34:12PM +0200, Norbert Szetei wrote:
> In vsock_update_buffer_size(), the buffer size was being clamped to the
> maximum first, and then to the minimum. If a user sets a minimum buffer
> size larger than the maximum, the minimum check overrides the maximum
> check, inverting the constraint.
>
> This breaks the intended socket memory boundaries by allowing the
> vsk->buffer_size to grow beyond the configured vsk->buffer_max_size.
>
> Fix this by checking the minimum first, and then the maximum. This
> ensures the buffer size never exceeds the buffer_max_size.
>
> Fixes: b9f2b0ffde0c ("vsock: handle buffer_size sockopts in the core")
> Suggested-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> Signed-off-by: Norbert Szetei <norbert@xxxxxxxxxxxx>
> ---
> v3:
> - Added Fixes and Suggested-by tags.
>
> net/vmw_vsock/af_vsock.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>