CVE-2022-49911

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> netfilter: ipset: enforce documented limit to prevent allocating huge memory<br /> <br /> Daniel Xu reported that the hash:net,iface type of the ipset subsystem does<br /> not limit adding the same network with different interfaces to a set, which<br /> can lead to huge memory usage or allocation failure.<br /> <br /> The quick reproducer is<br /> <br /> $ ipset create ACL.IN.ALL_PERMIT hash:net,iface hashsize 1048576 timeout 0<br /> $ for i in $(seq 0 100); do /sbin/ipset add ACL.IN.ALL_PERMIT 0.0.0.0/0,kaf_$i timeout 0 -exist; done<br /> <br /> The backtrace when vmalloc fails:<br /> <br /> [Tue Oct 25 00:13:08 2022] ipset: vmalloc error: size 1073741848, exceeds total pages<br /> <br /> [Tue Oct 25 00:13:08 2022] Call Trace:<br /> [Tue Oct 25 00:13:08 2022] <br /> [Tue Oct 25 00:13:08 2022] dump_stack_lvl+0x48/0x60<br /> [Tue Oct 25 00:13:08 2022] warn_alloc+0x155/0x180<br /> [Tue Oct 25 00:13:08 2022] __vmalloc_node_range+0x72a/0x760<br /> [Tue Oct 25 00:13:08 2022] ? hash_netiface4_add+0x7c0/0xb20<br /> [Tue Oct 25 00:13:08 2022] ? __kmalloc_large_node+0x4a/0x90<br /> [Tue Oct 25 00:13:08 2022] kvmalloc_node+0xa6/0xd0<br /> [Tue Oct 25 00:13:08 2022] ? hash_netiface4_resize+0x99/0x710<br /> <br /> <br /> The fix is to enforce the limit documented in the ipset(8) manpage:<br /> <br /> &gt; The internal restriction of the hash:net,iface set type is that the same<br /> &gt; network prefix cannot be stored with more than 64 different interfaces<br /> &gt; in a single set.