CVE-2026-80854

CVE CVE-2026-80854EUVD EUVD-2026-71304Published 2026-09-04T15:55:06.000Z

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux patch: 5.15.220; patch: 6.12.108; c52661d60f636d17e26ad834457db333bd1df494 <c39d0916da47d94909391876c9e5bd429ea7b1b9; c52661d60f636d17e26ad834457db333bd1df494 <85aa61fedcb4eb13f3dc5db73f6dc359f41f5d95; patch: 0; patch: 6.6.156; c52661d60f636d17e26ad834457db333bd1df494 <ad6f0375d2e93a1d8c015463e5e92dfcb26e311b; patch: 6.18.49; c52661d60f636d17e26ad834457db333bd1df494 <c494c5562ca69b61a82f566e3b87a445d2c28929; 3.5; c52661d60f636d17e26ad834457db333bd1df494 <178f59a0bccd3f66cdfa5184310f31a58b7257c4; c52661d60f636d17e26ad834457db333bd1df494 <bbd6aa311a9f4dd17822c7557451458d3d2e980b; c52661d60f636d17e26ad834457db333bd1df494 <c1f359d9a5efed458946063de65ddbeaacc4f165; patch: 7.3-rc1; patch: 7.2.3; c52661d60f636d17e26ad834457db333bd1df494 <eaa96a8458f54d6cf0954242ab8b1df2a6fccafa; c52661d60f636d17e26ad834457db333bd1df494 <2efbfd42441d3ef8137aff2d59e9835e1d5ae780; patch: 7.1.13; patch: 5.10.269; patch: 6.1.187

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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