Bug 2513169 (CVE-2026-68222)

Summary: CVE-2026-68222 kernel: media: msi2500: Return queued buffers on start_streaming() failure
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's `msi2500` media driver. This vulnerability occurs when the `start_streaming()` function fails to properly return queued buffers, causing them to leak. An attacker with local access could potentially exploit this to cause system instability or a denial of service (DoS) by triggering the driver's error paths. This issue is related to improper error handling within the driver.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-08-10 12:23:01 UTC
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").