CVE-2026-68222 media: msi2500: Return queued buffers on start_streaming() failure
A flaw in the msi2500 USB driver causes queued buffers to leak on streaming start failure, potentially leading to resource exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68222?
CVE-2026-68222 is a high-severity denial of service vulnerability in Linux, published on 10 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
media: msi2500: Return queued buffers on start_streaming() failure
The vb2 framework hands buffers to the driver via buf_queue() before calling start_streaming(). If start_streaming() returns an error without first returning those buffers via vb2_buffer_done(), vb2_start_streaming() fires WARN_ON(owned_by_drv_count) and the queued buffers leak.
msi2500_start_streaming() had five error paths that all hit this trap and were further tangled by ret-overwriting between calls:
- -ENODEV when the USB device was already disconnected - -ERESTARTSYS when mutex_lock_interruptible() was interrupted - msi2500_set_usb_adc() failure: ret was silently overwritten by the next call (msi2500_isoc_init), so the error was lost entirely - msi2500_isoc_init() failure: cleanup_queued_bufs was called, but the function then fell through to msi2500_ctrl_msg() and again masked the original error by overwriting ret - msi2500_ctrl_msg(CMD_START_STREAMING) failure: no cleanup at all, leaving isoc URBs submitted with no way for the driver to consume them
Consolidate the error paths into a small goto chain. Every failure now stops the function, drains the queued-buffer list, and returns the real error code. The ctrl_msg failure path also rolls back the preceding msi2500_isoc_init() via msi2500_isoc_cleanup() before unlocking and draining.
The cleanup helper takes a vb2_buffer_state argument so that the start_streaming error paths can pass VB2_BUF_STATE_QUEUED (as expected by userspace on start_streaming failure) while stop_streaming keeps its existing VB2_BUF_STATE_ERROR semantics.
This mirrors the uvcvideo fix in commit 4cf3b6fd54eb ("media: uvcvideo: Return queued buffers on start_streaming() failure").
Which versions are affected by CVE-2026-68222?
How do I fix CVE-2026-68222?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-68222 being exploited?
There is no known exploitation of CVE-2026-68222 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68222, DEBIAN-CVE-2026-68222, GHSA-c87f-75wq-m23q, UBUNTU-CVE-2026-68222.