CVE-2024-53212

/// Technical description

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

netlink: fix false positive warning in extack during dumps

Commit under fixes extended extack reporting to dumps.

It works under normal conditions, because extack errors are

usually reported during ->start() or the first ->dump(),

it's quite rare that the dump starts okay but fails later.

If the dump does fail later, however, the input skb will

already have the initiating message pulled, so checking

if bad attr falls within skb->data will fail.

Switch the check to using nlh, which is always valid.

syzbot found a way to hit that scenario by filling up

the receive queue. In this case we initiate a dump

but don't call ->dump() until there is read space for

an skb.

WARNING: CPU: 1 PID: 5845 at net/netlink/af_netlink.c:2210 netlink_ack_tlv_fill+0x1a8/0x560 net/netlink/af_netlink.c:2209

RIP: 0010:netlink_ack_tlv_fill+0x1a8/0x560 net/netlink/af_netlink.c:2209

Call Trace:

<TASK>

netlink_dump_done+0x513/0x970 net/netlink

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References