CVE-2024-36894: Linux kernel · usb: gadget: f_fs: Fix race between aio_cancel() and AIO request complete FFS based
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.4.0-1132.142~18.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 5.4.0-1132.142~18.04.1, 5.4.0-1137.144~18.04.1, 5.4.0-1136.145~18.04.1 +73
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 30 May 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
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")
References
- ubuntu.com/security/CVE-2024-36894 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-36894 (opens in a new tab)
- git.kernel.org/linus/24729b307eefcd7c476065cd7351c1a018082c19 (opens in a new tab)
- git.kernel.org/stable/c/73c05ad46bb4fbbdb346004651576d1c8dbcffbb (opens in a new tab)
- git.kernel.org/stable/c/d7461830823242702f5d84084bcccb25159003f4 (opens in a new tab)
- git.kernel.org/stable/c/24729b307eefcd7c476065cd7351c1a018082c19 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6955-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6949-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6952-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-3 (opens in a new tab)