NetSight
medium5.5

CVE-2025-38465

In the Linux kernel, the following vulnerability has been resolved: netlink: Fix wraparounds of sk->sk_rmem_alloc.

Impact

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

Affected products

VendorProductAffected versions
LinuxLinux Kernel
from 2.6.13 before 5.4.296
from 5.5 before 5.10.240
from 5.11 before 5.15.189
from 5.16 before 6.1.146
from 6.2 before 6.6.99
from 6.7 before 6.12.39
DebianDebian Linux
Version 11.0

Weakness classification

References