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CVE PROGRAM SOURCE RECORDUnscored

CVE-2026-80854

usb: gadget: f_tcm: keep port count until LUN teardown completes

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: keep port count until LUN teardown completes tcm_usbg_drop_nexus() permits session removal once tpg_port_count reaches zero. However, usbg_port_unlink() currently decrements that count from the fabric_pre_unlink() callback, before core_dev_del_lun() waits for active se_lun references to drain. If removal of the last LUN races a nexus removal, the latter can observe a zero port count and call target_remove_session(). This frees sess_cmd_map while an in-flight struct usbg_cmd, including its work item, can still be accessed. Overlapping the last-LUN unlink with nexus removal reproduces this lifetime violation as a DEBUG_OBJECTS "free active" warning for usbg_cmd_work, followed by a target-core BUG/Oops. The generic target-core unlink path has no callback after core_dev_del_lun() completes. Add an optional fabric_post_unlink() callback and use it for the f_tcm port count. The count now remains nonzero until core_dev_del_lun() has finished draining active LUN references, preventing nexus removal from freeing the session during command completion.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • c52661d60f636d17e26ad834457db333bd1df494 to < c494c5562ca69b61a82f566e3b87a445d2c28929affected
  • c52661d60f636d17e26ad834457db333bd1df494 to < c1f359d9a5efed458946063de65ddbeaacc4f165affected
  • c52661d60f636d17e26ad834457db333bd1df494 to < 178f59a0bccd3f66cdfa5184310f31a58b7257c4affected
  • c52661d60f636d17e26ad834457db333bd1df494 to < ad6f0375d2e93a1d8c015463e5e92dfcb26e311baffected
  • c52661d60f636d17e26ad834457db333bd1df494 to < 2efbfd42441d3ef8137aff2d59e9835e1d5ae780affected
  • c52661d60f636d17e26ad834457db333bd1df494 to < 85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95affected
  • c52661d60f636d17e26ad834457db333bd1df494 to < bbd6aa311a9f4dd17822c7557451458d3d2e980baffected
  • c52661d60f636d17e26ad834457db333bd1df494 to < eaa96a8458f54d6cf0954242ab8b1df2a6fccafaaffected
  • c52661d60f636d17e26ad834457db333bd1df494 to < c39d0916da47d94909391876c9e5bd429ea7b1b9affected

Linux Linux

Default version status: affected

  • 3.5affected
  • 0 to < 3.5unaffected
  • 5.10.269 to ≤ 5.10.*unaffected
  • 5.15.220 to ≤ 5.15.*unaffected
  • 6.1.187 to ≤ 6.1.*unaffected
  • 6.6.156 to ≤ 6.6.*unaffected
  • 6.12.108 to ≤ 6.12.*unaffected
  • 6.18.49 to ≤ 6.18.*unaffected
  • 7.1.13 to ≤ 7.1.*unaffected
  • 7.2.3 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References