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://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.14
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.7
https://sites.google.com/view/syzscope/kasan-use-after-free-read-in-cipso_v4_genopt
https://syzkaller.appspot.com/bug?id=96e7d345748d8814901c91cd92084ed04b46701e
Source: MITRE
Published: 2021-05-14
Updated: 2021-06-09
Type: CWE-416
Base Score: 4.6
Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P
Impact Score: 6.4
Exploitability Score: 3.9
Severity: MEDIUM
Base Score: 7.8
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 1.8
Severity: HIGH