Re: [PATCH net-next v3 01/23] net: page_pool: sanitise allocation order

On Mon, Aug 18, 2025 at 6:56 AM Pavel Begunkov [off-list ref] wrote:

We're going to give more control over rx buffer sizes to user space, and
since we can't always rely on driver validation, let's sanitise it in
page_pool_init() as well. Note that we only need to reject over
MAX_PAGE_ORDER allocations for normal page pools, as current memory
providers don't need to use the buddy allocator and must check the order
on init.

Suggested-by: Stanislav Fomichev <redacted>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>

Reviewed-by: Mina Almasry <redacted>

I think I noticed an unrelated bug in this code and we need this fix?

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 343a6cac21e3..ba70569bd4b0 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -287,8 +287,10 @@ static int page_pool_init(struct page_pool *pool,
        }

        if (pool->mp_ops) {
-               if (!pool->dma_map || !pool->dma_sync)
-                       return -EOPNOTSUPP;
+               if (!pool->dma_map || !pool->dma_sync) {
+                       err = -EOPNOTSUPP;
+                       goto free_ptr_ring;
+               }

                if (WARN_ON(!is_kernel_rodata((unsigned long)pool->mp_ops))) {
                        err = -EFAULT;

I'll send a separate fix.


--
Thanks,
Mina