Backport RXRPC for 6.1.y from 6.2

[Jeffrey E Altman]

On 5/10/2026 1:41 PM, Wentao Guan wrote:
>> Are you associated with a Linux distribution which ships 6.1.y stable?
> We shiped 6.1 kernel past, and we are preparing the fix for it.
>
> BRs
> Wentao Guan

Wentao,

Have you confirmed that 6.1.179 is vulnerable to the exploit? When 
processing
a DATA packet a new unshared skb is allocated for the incoming packet
whenever decryption is required.

         /* Unshare the packet so that it can be modified for in-place
          * decryption.
          */
         if (sp->hdr.securityIndex != 0) {
             struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
             if (!nskb) {
                 rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
                 goto out;
             }

             if (nskb != skb) {
                 rxrpc_eaten_skb(skb, rxrpc_skb_received);
                 skb = nskb;
                 rxrpc_new_skb(skb, rxrpc_skb_unshared);
                 sp = rxrpc_skb(skb);
             }
         }

I cannot easily check but it doesn't look like 6.1.179 is vulnerable to 
CVE-2026-43500.

Please check.

Thank you.

Jeffrey Altman


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