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.

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-27060
https://www.cve.org/CVERecord?id=CVE-2024-27060
https://git.kernel.org/stable/c/ce64ba1f6ec3439e4b4d880b4db99673f4507228
https://git.kernel.org/stable/c/d3d17e23d1a0d1f959b4fa55b35f1802d9c584fa
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-27060.mbox
https://bugzilla.redhat.com/show_bug.cgi?id=2278393