CVE-2024-53212 netlink: fix false positive warning in extack during dumps
A local attacker can trigger a kernel warning and potential denial of service by filling the receive queue during netlink dumps.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-53212?
CVE-2024-53212 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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/af_netlink.c:2250 netlink_dump+0x91f/0xe10 net/netlink/af_netlink.c:2351 netlink_recvmsg+0x6bb/0x11d0 net/netlink/af_netlink.c:1983 sock_recvmsg_nosec net/socket.c:1051 [inline] sock_recvmsg+0x22f/0x280 net/socket.c:1073 __sys_recvfrom+0x246/0x3d0 net/socket.c:2267 __do_sys_recvfrom net/socket.c:2285 [inline] __se_sys_recvfrom net/socket.c:2281 [inline] __x64_sys_recvfrom+0xde/0x100 net/socket.c:2281 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff37dd17a79
Which versions are affected by CVE-2024-53212?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-53212?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-53212 being exploited?
There is no known exploitation of CVE-2024-53212 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-53212, DEBIAN-CVE-2024-53212, GHSA-g32c-gvpp-qqg5, UBUNTU-CVE-2024-53212.