CVE-2024-36894

MEDIUM
Published May 30, 2024 Modified May 12, 2026 CWE-362

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")

Is your site exposed to CVE-2024-36894?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.6
MEDIUM
CVSS:3.1/AV:P/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H

Weakness Type (CWE)

CWE-362 CWE-362

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/24729b307eefcd7c476065cd7351c1a018082c19 https://git.kernel.org/stable/c/3613e5023f09b3308545e9d1acda86017ebd418a https://git.kernel.org/stable/c/73c05ad46bb4fbbdb346004651576d1c8dbcffbb https://git.kernel.org/stable/c/9e72ef59cbe61cd1243857a6418ca92104275867 https://git.kernel.org/stable/c/a0fdccb1c9e027e3195f947f61aa87d6d0d2ea14 https://git.kernel.org/stable/c/d7461830823242702f5d84084bcccb25159003f4 https://git.kernel.org/stable/c/e500b1c4e29ad0bd1c1332a1eaea2913627a92dd https://git.kernel.org/stable/c/f71a53148ce34898fef099b75386a3a9f4449311 https://git.kernel.org/stable/c/24729b307eefcd7c476065cd7351c1a018082c19 https://git.kernel.org/stable/c/3613e5023f09b3308545e9d1acda86017ebd418a https://git.kernel.org/stable/c/73c05ad46bb4fbbdb346004651576d1c8dbcffbb https://git.kernel.org/stable/c/9e72ef59cbe61cd1243857a6418ca92104275867 https://git.kernel.org/stable/c/a0fdccb1c9e027e3195f947f61aa87d6d0d2ea14 https://git.kernel.org/stable/c/d7461830823242702f5d84084bcccb25159003f4 https://git.kernel.org/stable/c/e500b1c4e29ad0bd1c1332a1eaea2913627a92dd https://git.kernel.org/stable/c/f71a53148ce34898fef099b75386a3a9f4449311

Frequently Asked Questions

What is CVE-2024-36894? +
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") It has a CVSS v3.1 base score of 5.6 (MEDIUM).
How severe is CVE-2024-36894? +
CVE-2024-36894 has a CVSS v3.1 score of 5.6 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2024-36894? +
CVE-2024-36894 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-36894? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-41458

OwnTone Server versions 28.4 through 29.0 contain a race condition vulnerability in the DAAP login handler that allows unauthenticated attackers …
CVE-2025-13036

An authentication bypass security issue exists within FactoryTalk Historian Site Edition. By continually sending requests to the login endpoint, an …
CVE-2025-0372

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in HYPR Passwordless on Windows allows Privilege Escalation.This issue …
CVE-2025-59052

Angular is a development platform for building mobile and desktop web applications using TypeScript/JavaScript and other languages. Angular uses a …
CVE-2024-47534

go-tuf is a Go implementation of The Update Framework (TUF). The go-tuf client inconsistently traces the delegations. For example, if …
CVE-2025-64118

node-tar is a Tar for Node.js. In 7.5.1, using .t (aka .list) with { sync: true } to read tar …

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2024-36894 — free, no signup required.