CVE-2026-68367 — usb: gadget: f_tcm: synchronize delayed set_alt with teardown
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_tcm: synchronize delayed set_alt with teardown The f_tcm set_alt() path defers endpoint setup to a work item and completes the delayed status response from process context. The delayed work uses f_tcm private state and may complete the setup request after disconnect or function teardown has already moved on. Cancel and drain the delayed set_alt work when the function is unbound or freed. For disable paths, which are reached under the composite device lock, use a small state machine and a non-sleeping cancellation path instead of cancel_work_sync(). If the work is already running, mark it cancelled and let the worker own the cleanup; otherwise tcm_disable() can cancel the queued work and clean up immediately. Also serialize the final delayed-status completion with the cancellation check while holding the composite device lock. This prevents a disconnect from clearing delayed_status while the worker is about to complete the control request. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in tcm_delayed_set_alt+0x6c/0xef0 Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? tcm_delayed_set_alt+0x6c/0xef0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x188/0x320 ? tcm_delayed_set_alt+0x6c/0xef0 kasan_report+0xe0/0x110 ? tcm_delayed_set_alt+0x6c/0xef0 tcm_delayed_set_alt+0x6c/0xef0 ? __pfx_tcm_delayed_set_alt+0x10/0x10 ? process_one_work+0x4cb/0xb90 ? rcu_is_watching+0x20/0x50 ? tcm_delayed_set_alt+0x9/0xef0 process_one_work+0x4d7/0xb90 ? __pfx_process_one_work+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __list_add_valid_or_report+0x37/0xf0 ? __pfx_tcm_delayed_set_alt+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 worker_thread+0x2d8/0x570 ? __pfx_worker_thread+0x10/0x10 kthread+0x1ad/0x1f0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x3c9/0x540 ? __pfx_ret_from_fork+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __switch_to+0x2e9/0x730 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 544: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 tcm_alloc+0x68/0x180 usb_get_function+0x36/0x60 config_usb_cfg_link+0x125/0x1b0 configfs_symlink+0x322/0x890 vfs_symlink+0xc2/0x270 filename_symlinkat+0x295/0x2f0 __x64_sys_symlinkat+0x62/0x90 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 661: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x43/0x70 kfree+0x2f9/0x530 config_usb_cfg_unlink+0x173/0x1e0 configfs_unlink+0x1fa/0x340 vfs_unlink+0x15c/0x510 filename_unlinkat+0x2ba/0x450 __x64_sys_unlinkat+0x63/0x90 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ c52661d60f636d17e26ad834457db333bd1df494 and < 8fb317058d165c88f3344f59439c14872c162b3c≥ c52661d60f636d17e26ad834457db333bd1df494 and < 90431d8523c0c1c9f8e3e3f0895727063f93da85≥ c52661d60f636d17e26ad834457db333bd1df494 and < ee07d09419f1c59c74f73107aa08444f2f2fc6c8≥ c52661d60f636d17e26ad834457db333bd1df494 and < 3118bb872c7dff653294f193d5328a476619e04d≥ c52661d60f636d17e26ad834457db333bd1df494 and < a6eb5a0ae7cd313cfd7df78decd8f43b64c68703≥ c52661d60f636d17e26ad834457db333bd1df494 and < f282242906c12fd476b86757afba51f211d4f959≥ c52661d60f636d17e26ad834457db333bd1df494 and < 4c6c6a5588b9a2f8437fb794e852d05fa60ebe53≥ c52661d60f636d17e26ad834457db333bd1df494 and < 79e2d75725c85607f8a9d87ae9cace62a19f767d and 1 moreversion 3.5 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 30, 2026 · 15 reading(s) · max 0.18%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/90431d8523c0c1c9f8e3e3f0895727063f93da85
- git.kernel.org/stable/c/79e2d75725c85607f8a9d87ae9cace62a19f767d
- git.kernel.org/stable/c/ee07d09419f1c59c74f73107aa08444f2f2fc6c8
- git.kernel.org/stable/c/a6eb5a0ae7cd313cfd7df78decd8f43b64c68703
- git.kernel.org/stable/c/4c6c6a5588b9a2f8437fb794e852d05fa60ebe53
- git.kernel.org/stable/c/3118bb872c7dff653294f193d5328a476619e04d
- git.kernel.org/stable/c/f282242906c12fd476b86757afba51f211d4f959
- git.kernel.org/stable/c/8fb317058d165c88f3344f59439c14872c162b3c
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 2d
- Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 2d
- Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 2d
- Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 2d
- Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 2d
- Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-68367 is "usb: gadget: f_tcm: synchronize delayed set_alt with teardown", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.18% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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