CVE-2026-68209 media: sun4i-csi: Return queued buffers on start_streaming() failure
A bug in the sun4i-csi driver causes queued buffers to leak when start_streaming fails, 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-2026-68209?
CVE-2026-68209 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: sun4i-csi: 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.
sun4i_csi_start_streaming() returned -EINVAL when no matching CSI format could be found, before any setup (scratch buffer allocation, pipeline start) had been performed. The remaining error paths already converge on the err_clear_dma_queue label, which calls return_all_buffers(..., VB2_BUF_STATE_QUEUED) under csi->qlock. Jump to that label directly: the intermediate err_disable_device / err_disable_pipeline / err_free_scratch_buffer labels are skipped, which is correct because nothing they would undo has happened yet.
This mirrors the uvcvideo fix in commit 4cf3b6fd54eb ("media: uvcvideo: Return queued buffers on start_streaming() failure").
Which versions are affected by CVE-2026-68209?
How do I fix CVE-2026-68209?
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-2026-68209 being exploited?
There is no known exploitation of CVE-2026-68209 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-68209, DEBIAN-CVE-2026-68209, GHSA-93x6-mg2w-rrg6, UBUNTU-CVE-2026-68209.