Bug 2536576 (CVE-2026-93042) - CVE-2026-93042 kernel: dmaengine: dw-edma: Terminate all descriptors without callbacks
Summary: CVE-2026-93042 kernel: dmaengine: dw-edma: Terminate all descriptors without ...
Keywords:
Status: NEW
Alias: CVE-2026-93042
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 18:29 UTC by OSIDB Bzimport
Modified: 2026-10-20 11:26 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-09-17 18:29:52 UTC
In the Linux kernel, the following vulnerability has been resolved:

dmaengine: dw-edma: Terminate all descriptors without callbacks

The DMA Engine client documentation says in the "Terminate APIs" section
of Documentation/driver-api/dmaengine/client.rst:

"No callback functions will be called for any incomplete transfers."

dw-edma instead calls vchan_cookie_complete() when a deferred STOP reaches
the interrupt handler. This schedules a callback for the active descriptor
and leaves other issued or submitted descriptors queued. A late callback
after dmaengine_terminate_sync() can dereference client state that has
already been freed, while leftover descriptors may later restart into
reused buffers or leak.

Move all issued and submitted descriptors to the terminated list whenever
termination completes. For a pending STOP, do this from both the DONE and
ABORT paths. Complete their cookies in order without scheduling callbacks.

A STOP can remain pending until the running transfer raises an
interrupt. Make device_synchronize() wait for such a pending STOP to
complete before releasing terminated descriptors. Reuse it from
free_chan_resources(), then release the remaining virt-dma resources.
Sleep instead of busy-polling while waiting, and warn if the existing
timeout expires.


Note You need to log in before you can comment on or make changes to this bug.