The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.
https://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701e
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genopt
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.14