CVE-2024-27060: thunderbolt: Fix NULL pointer dereference in tb_port_update_credits()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-01 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Fix NULL pointer dereference in tb_port_update_credits() Olliver reported that his system crashes when plugging in Thunderbolt 1 device: BUG: kernel NULL pointer dereference, address: 0000000000000020 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI RIP: 0010:tb_port_do_update_credits+0x1b/0x130 [thunderbolt] Call Trace: <TASK> ? __die+0x23/0x70 ? page_fault_oops+0x171/0x4e0 ? exc_page_fault+0x7f/0x180 ? asm_exc_page_fault+0x26/0x30 ? tb_port_do_update_credits+0x1b/0x130 ? tb_switch_update_link_attributes+0x83/0xd0 tb_switch_add+0x7a2/0xfe0 tb_scan_port+0x236/0x6f0 tb_handle_hotplug+0x6db/0x900 process_one_work+0x171/0x340 worker_thread+0x27b/0x3a0 ? __pfx_worker_thread+0x10/0x10 kthread+0xe5/0x120 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> This is due the fact that some Thunderbolt 1 devices only have one lane adapter. Fix this by checking for the lane 1 before we read its credits.

Affected products

Linux kernel: from 6.7 before 6.7.12; 6.8-rc1, 6.8-rc2, 6.8-rc3, 6.8-rc4, 6.8-rc5, 6.8-rc6 — fixed in 6.7.12

How to fix

Upgrade to a fixed version: Linux kernel 6.7.12. Check the vendor advisory for mitigations.

References

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