page_pool_dev_alloc_pages could return NULL. There was a WARN_ON(!page)
but it would still proceed to use the NULL pointer and then crash.

This is similar to commit 001ba0902046
("net: fec: handle page_pool_dev_alloc_pages error").

This is found by our static analysis tool KNighter.

Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
Fixes: 3c47e8ae113a ("net: libwx: Support to receive packets in NAPI")
---
 drivers/net/ethernet/wangxun/libwx/wx_lib.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/wangxun/libwx/wx_lib.c b/drivers/net/ethernet/wangxun/libwx/wx_lib.c
index 00b0b318df27..d567443b1b20 100644
--- a/drivers/net/ethernet/wangxun/libwx/wx_lib.c
+++ b/drivers/net/ethernet/wangxun/libwx/wx_lib.c
@@ -310,7 +310,8 @@ static bool wx_alloc_mapped_page(struct wx_ring *rx_ring,
 		return true;
 
 	page = page_pool_dev_alloc_pages(rx_ring->page_pool);
-	WARN_ON(!page);
+	if (unlikely(!page))
+		return false;
 	dma = page_pool_get_dma_addr(page);
 
 	bi->page_dma = dma;
-- 
2.34.1

On Mon, Apr 07, 2025 at 01:49:52PM -0500, Chenyuan Yang wrote:
> page_pool_dev_alloc_pages could return NULL. There was a WARN_ON(!page)
> but it would still proceed to use the NULL pointer and then crash.
> 
> This is similar to commit 001ba0902046
> ("net: fec: handle page_pool_dev_alloc_pages error").
> 
> This is found by our static analysis tool KNighter.
> 
> Signed-off-by: Chenyuan Yang <chenyuan0y@gmail.com>
> Fixes: 3c47e8ae113a ("net: libwx: Support to receive packets in NAPI")
> ---
>  drivers/net/ethernet/wangxun/libwx/wx_lib.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Joe Damato <jdamato@fastly.com>