CVE-2026-98555
Received Received - Intake

Double Free and Memory Leak in Linux Kernel LLC Module

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: llc: fix skb UAF and leaks on llc_mac_hdr_init() failure In llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr(), if llc_mac_hdr_init() fails, kfree_skb(skb) is called instead of kfree_skb(nskb). This leaks the newly allocated nskb, reads from the freed skb via LLC_I_GET_NR(pdu), and double-frees skb when llc_conn_state_process() drops its reference. In llc_sap_action_send_xid_r() and llc_sap_action_send_test_r(), nskb is leaked if llc_mac_hdr_init() returns an error. Free nskb in all three error paths.

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98555
EUVD
EUVD-2026-103600

Affected Vendors & Products

Showing 9 associated CPEs
Vendor Product Version / Range
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Linux Linux 2.6.12

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a use-after-free (UAF) and memory leak vulnerability in the Linux kernel's LLC (Logical Link Control) module. It occurs when llc_mac_hdr_init() fails, leading to incorrect cleanup where skb is freed instead of nskb, causing double-free and memory leaks. The issue affects three functions: llc_conn_ac_resend_i_xxx_x_set_0_or_send_rr, llc_sap_action_send_xid_r, and llc_sap_action_send_test_r.

Impact Analysis

This vulnerability can cause system instability, crashes, or privilege escalation if exploited. It may lead to denial-of-service conditions or unauthorized access due to memory corruption. Systems running vulnerable Linux kernel versions are at risk.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the LLC skb UAF and leak issues. Monitor kernel logs for LLC-related errors or crashes.

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