CVE-2024-41066: ibmvnic: Add tx check to prevent skb leak

In the Linux kernel, the following vulnerability has been resolved:

ibmvnic: Add tx check to prevent skb leak

Below is a summary of how the driver stores a reference to an skb during transmit: txbuff[freemap[consumerindex]]->skb = newskb; freemap[consumerindex] = IBMVNICINVALIDMAP; consumerindex ++; Where variable data looks like this: freemap == [4, IBMVNICINVALIDMAP, IBMVNICINVALIDMAP, 0, 3] consumerindex^ txbuff == [skb=null, skb=<ptr>, skb=<ptr>, skb=null, skb=null]

The driver has checks to ensure that freemap[consumerindex] pointed to a valid index but there was no check to ensure that this index pointed to an unused/null skb address. So, if, by some chance, our freemap and txbuff lists become out of sync then we were previously risking an skb memory leak. This could then cause tcp congestion control to stop sending packets, eventually leading to ETIMEDOUT.

Therefore, add a conditional to ensure that the skb address is null. If not then warn the user (because this is still a bug that should be patched) and free the old pointer to prevent memleak/tcp problems.

— Red Hat

This CVE was automatically created from a reference found in an email or other text. If you are reading this, then this CVE entry is probably erroneous, since this text should be replaced by the official CVE description automatically.

— Launchpad