Patch "net: usb: sr9700: stop lying about skb->truesize" has been added to the 6.9-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: usb: sr9700: stop lying about skb->truesize

to the 6.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-usb-sr9700-stop-lying-about-skb-truesize.patch
and it can be found in the queue-6.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 4e85d5045cb4390eeffc4102ae924be1a2194d33
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date:   Mon May 6 14:39:39 2024 +0000

    net: usb: sr9700: stop lying about skb->truesize
    
    [ Upstream commit 05417aa9c0c038da2464a0c504b9d4f99814a23b ]
    
    Some usb drivers set small skb->truesize and break
    core networking stacks.
    
    In this patch, I removed one of the skb->truesize override.
    
    I also replaced one skb_clone() by an allocation of a fresh
    and small skb, to get minimally sized skbs, like we did
    in commit 1e2c61172342 ("net: cdc_ncm: reduce skb truesize
    in rx path") and 4ce62d5b2f7a ("net: usb: ax88179_178a:
    stop lying about skb->truesize")
    
    Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support")
    Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240506143939.3673865-1-edumazet@xxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/usb/sr9700.c b/drivers/net/usb/sr9700.c
index 3164451e1010c..0a662e42ed965 100644
--- a/drivers/net/usb/sr9700.c
+++ b/drivers/net/usb/sr9700.c
@@ -421,19 +421,15 @@ static int sr9700_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
 			skb_pull(skb, 3);
 			skb->len = len;
 			skb_set_tail_pointer(skb, len);
-			skb->truesize = len + sizeof(struct sk_buff);
 			return 2;
 		}
 
-		/* skb_clone is used for address align */
-		sr_skb = skb_clone(skb, GFP_ATOMIC);
+		sr_skb = netdev_alloc_skb_ip_align(dev->net, len);
 		if (!sr_skb)
 			return 0;
 
-		sr_skb->len = len;
-		sr_skb->data = skb->data + 3;
-		skb_set_tail_pointer(sr_skb, len);
-		sr_skb->truesize = len + sizeof(struct sk_buff);
+		skb_put(sr_skb, len);
+		memcpy(sr_skb->data, skb->data + 3, len);
 		usbnet_skb_return(dev, sr_skb);
 
 		skb_pull(skb, len + SR_RX_OVERHEAD);