CVE-2026-93286

Received Received - Intake

NULL Pointer Dereference in Linux Kernel AppleTalk

Publication date: 2026-09-24

Last updated on: 2026-10-03

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: net: appletalk: fix NULL pointer dereference in aarp_send_ddp() aarp_send_ddp() calls atalk_find_dev_addr(dev) in the LocalTalk fast path without checking for NULL. When the device has no AppleTalk interface configured (dev->atalk_ptr == NULL), this leads to a NULL pointer dereference at the at->s_net access. KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:aarp_send_ddp (net/appletalk/aarp.c:552 (discriminator 2)) Call Trace: <TASK> atalk_sendmsg (net/appletalk/ddp.c:1715) __sys_sendto (net/socket.c:2265 (discriminator 1)) __x64_sys_sendto (net/socket.c:2272) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Add a NULL check consistent with the other callers of atalk_find_dev_addr().

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-24

Last Modified

2026-10-03

Generated

2026-10-15

AI Q&A

2026-09-25

EPSS Evaluated

2026-10-13

NVD

CVE-2026-93286

EUVD

EUVD-2026-86165

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a NULL pointer dereference vulnerability in the Linux kernel's AppleTalk networking subsystem. The function aarp_send_ddp() fails to check if the network device has an AppleTalk interface configured before accessing its address information. When dev->atalk_ptr is NULL, the code attempts to access at->s_net which causes a crash.

Detection Guidance

This vulnerability can be detected by checking for kernel crashes or NULL pointer dereference errors in the appletalk module. Monitor system logs for KASAN reports or kernel oops messages related to aarp_send_ddp. No specific commands are provided in the context.

Impact Analysis

This vulnerability could cause a system crash (kernel panic) when sending AppleTalk network packets on a device without AppleTalk configured. This leads to denial of service for the affected system and any services relying on network connectivity.

Compliance Impact

This vulnerability is a local denial-of-service issue in the Linux kernel's AppleTalk networking subsystem. It does not directly impact data confidentiality, integrity, or privacy controls required by standards like GDPR or HIPAA. The issue only causes a kernel crash when specific network operations are performed under rare conditions, without exposing sensitive data or violating access controls.

Mitigation Strategies

Apply the Linux kernel patch that adds a NULL check in aarp_send_ddp. Disable the AppleTalk protocol on systems where it is not required. Update to a patched kernel version if available.

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