CVE-2024-36894 — usb: gadget: f_fs: Fix race between aio_cancel() and AIO request complete
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_fs: Fix race between aio_cancel() and AIO request complete FFS based applications can utilize the aio_cancel() callback to dequeue pending USB requests submitted to the UDC. There is a scenario where the FFS application issues an AIO cancel call, while the UDC is handling a soft disconnect. For a DWC3 based implementation, the callstack looks like the following: DWC3 Gadget FFS Application dwc3_gadget_soft_disconnect() ... --> dwc3_stop_active_transfers() --> dwc3_gadget_giveback(-ESHUTDOWN) --> ffs_epfile_async_io_complete() ffs_aio_cancel() --> usb_ep_free_request() --> usb_ep_dequeue() There is currently no locking implemented between the AIO completion handler and AIO cancel, so the issue occurs if the completion routine is running in parallel to an AIO cancel call coming from the FFS application. As the completion call frees the USB request (io_data->req) the FFS application is also referencing it for the usb_ep_dequeue() call. This can lead to accessing a stale/hanging pointer. commit b566d38857fc ("usb: gadget: f_fs: use io_data->status consistently") relocated the usb_ep_free_request() into ffs_epfile_async_io_complete(). However, in order to properly implement locking to mitigate this issue, the spinlock can't be added to ffs_epfile_async_io_complete(), as usb_ep_dequeue() (if successfully dequeuing a USB request) will call the function driver's completion handler in the same context. Hence, leading into a deadlock. Fix this issue by moving the usb_ep_free_request() back to ffs_user_copy_worker(), and ensuring that it explicitly sets io_data->req to NULL after freeing it within the ffs->eps_lock. This resolves the race condition above, as the ffs_aio_cancel() routine will not continue attempting to dequeue a request that has already been freed, or the ffs_user_copy_work() not freeing the USB request until the AIO cancel is done referencing it. This fix depends on commit b566d38857fc ("usb: gadget: f_fs: use io_data->status consistently")
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
- Technical severity (high)+6
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.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
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, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (logic error), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
version 3.15≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < 24729b307eefcd7c476065cd7351c1a018082c19≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < d7461830823242702f5d84084bcccb25159003f4≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < 73c05ad46bb4fbbdb346004651576d1c8dbcffbb≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < a0fdccb1c9e027e3195f947f61aa87d6d0d2ea14≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < 3613e5023f09b3308545e9d1acda86017ebd418a≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < e500b1c4e29ad0bd1c1332a1eaea2913627a92dd≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < 9e72ef59cbe61cd1243857a6418ca92104275867 and 1 more≥ 2e4c7553cd6f9c68bb741582dcb614edcbeca70f and < f71a53148ce34898fef099b75386a3a9f4449311 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 6.9-rc5version 6.9-rc6≥ 3.15 and < 4.19.317version 6.9-rc4version 6.9-rc3version 6.9-rc2version 6.9-rc1≥ 6.7 and < 6.8.10 and 5 more≥ 6.2 and < 6.6.31≥ 5.16 and < 6.1.95≥ 5.11 and < 5.15.162≥ 5.5 and < 5.10.221≥ 4.20 and < 5.4.279 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
| 5.6 | CVSS 3.1 | Medium | 0.4 | 5.2 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 5.6 | CVSS 3.1 | Medium | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2024
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 14, 2026 – Oct 14, 2026
- 1× Official description updated · Oct 14, 2026 – Oct 14, 2026
References
11 on the record
- git.kernel.org/stable/c/f71a53148ce34898fef099b75386a3a9f4449311
- git.kernel.org/stable/c/73c05ad46bb4fbbdb346004651576d1c8dbcffbb
- git.kernel.org/stable/c/d7461830823242702f5d84084bcccb25159003f4
- git.kernel.org/stable/c/a0fdccb1c9e027e3195f947f61aa87d6d0d2ea14
- git.kernel.org/stable/c/3613e5023f09b3308545e9d1acda86017ebd418a
- git.kernel.org/stable/c/9e72ef59cbe61cd1243857a6418ca92104275867
- git.kernel.org/stable/c/24729b307eefcd7c476065cd7351c1a018082c19
- git.kernel.org/stable/c/e500b1c4e29ad0bd1c1332a1eaea2913627a92dd
- cert-portal.siemens.com/productcert/html/ssa-355557.html
- cert-portal.siemens.com/productcert/html/ssa-265688.html
- lists.debian.org/debian-lts-announce/2025/01/msg00001.html
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
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 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-2024-36894 is "usb: gadget: f_fs: Fix race between aio_cancel() and AIO request complete", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.20% 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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