[PATCH 21/34] net: mana: Check if netdev/napi_alloc_frag returns single page

netdev/napi_alloc_frag() may fall back to single page which is smaller
than the requested size.
Add error checking to avoid memory overwritten.

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(cherry picked from commit df18f2da302f169e1a29098c6ca3b474f1b0269e)
Signed-off-by: Bastian Blank <waldi@debian.org>
Gbp-Pq: Topic features/all/ethernet-microsoft
Gbp-Pq: Name 0021-net-mana-Check-if-netdev-napi_alloc_frag-returns-sin.patch

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 1666f8cec60dc21ce53d013e673dc3a62c45d19e..8ca95633f84561bdb8804a5d09b5974bd4d2e6c5 100644 (file)
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -554,6 +554,14 @@ static int mana_pre_alloc_rxbufs(struct mana_port_context *mpc, int new_mtu)
                        va = netdev_alloc_frag(mpc->rxbpre_alloc_size);
                        if (!va)
                                goto error;
+
+                       page = virt_to_head_page(va);
+                       /* Check if the frag falls back to single page */
+                       if (compound_order(page) <
+                           get_order(mpc->rxbpre_alloc_size)) {
+                               put_page(page);
+                               goto error;
+                       }
                } else {
                        page = dev_alloc_page();
                        if (!page)
@@ -1510,6 +1518,13 @@ static void *mana_get_rxfrag(struct mana_rxq *rxq, struct device *dev,
 
                if (!va)
                        return NULL;
+
+               page = virt_to_head_page(va);
+               /* Check if the frag falls back to single page */
+               if (compound_order(page) < get_order(rxq->alloc_size)) {
+                       put_page(page);
+                       return NULL;
+               }
        } else {
                page = dev_alloc_page();
                if (!page)