CVE-2025-38465

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netlink: Fix wraparounds of sk-&gt;sk_rmem_alloc.<br /> <br /> Netlink has this pattern in some places<br /> <br /> if (atomic_read(&amp;sk-&gt;sk_rmem_alloc) &gt; sk-&gt;sk_rcvbuf)<br /> atomic_add(skb-&gt;truesize, &amp;sk-&gt;sk_rmem_alloc);<br /> <br /> , which has the same problem fixed by commit 5a465a0da13e ("udp:<br /> Fix multiple wraparounds of sk-&gt;sk_rmem_alloc.").<br /> <br /> For example, if we set INT_MAX to SO_RCVBUFFORCE, the condition<br /> is always false as the two operands are of int.<br /> <br /> Then, a single socket can eat as many skb as possible until OOM<br /> happens, and we can see multiple wraparounds of sk-&gt;sk_rmem_alloc.<br /> <br /> Let&amp;#39;s fix it by using atomic_add_return() and comparing the two<br /> variables as unsigned int.<br /> <br /> Before:<br /> [root@fedora ~]# ss -f netlink<br /> Recv-Q Send-Q Local Address:Port Peer Address:Port<br /> -1668710080 0 rtnl:nl_wraparound/293 *<br /> <br /> After:<br /> [root@fedora ~]# ss -f netlink<br /> Recv-Q Send-Q Local Address:Port Peer Address:Port<br /> 2147483072 0 rtnl:nl_wraparound/290 *<br /> ^<br /> `--- INT_MAX - 576