CVE-2023-53332: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53332 is a NULL pointer dereference vulnerability in the Linux kernel's genirq/ipi interrupt handling subsystem. It affects Linux kernel versions from 4.6 up to (but not including) 6.1.18, and from 6.2 up to (but not including) 6.2.5. The flaw was discovered by the Linux Verification Center (linuxtesting.org) using the SVACE static analysis tool and was publicly disclosed on September 16, 2025. It carries a CVSS v3.1 base score of 5.5 (Medium) (Red Hat Advisory, Red Hat Bugzilla).

The root cause is a missing NULL pointer check (CWE-476) in the ipi_send_verify() function within the kernel's genirq/ipi component. When ipi_send_mask() or ipi_send_single() is called with an invalid interrupt number, all local variables are set to NULL. The ipi_send_verify() function, invoked from these callers, fails to validate its data parameter before passing it to irq_data_get_affinity_mask(), which then dereferences the NULL pointer and triggers a kernel oops. The fix adds the missing NULL check in ipi_send_verify() before the dereference occurs (Red Hat Bugzilla, Kernel Patch 1).

Successful exploitation causes a kernel oops (panic/crash), resulting in a denial of service condition on the affected system. The impact is limited to availability — there is no confidentiality or integrity impact. A local attacker with low privileges could crash the system, potentially disrupting all services running on the host (Red Hat Advisory, Red Hat Bugzilla).

There is no public proof-of-concept exploit code and no evidence of in-the-wild exploitation as of the time of disclosure. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.017% (0.000170), indicating a very low probability of exploitation in the near term (Red Hat Advisory).

Update the Linux kernel to version 6.1.18 or later (for the 6.1.x stable branch), or to version 6.2.5 or later (for the 6.2.x branch). Official upstream patches are available in the kernel stable tree. As a compensating control, restricting local user access to minimize the attack surface is advisable until patching is feasible (Red Hat Advisory, Kernel Patch 1, Kernel Patch 2, Kernel Patch 3).