CVE-2021-47533

Summary

In the Linux kernel, the following vulnerability has been resolved:

drm/vc4: kms: Clear the HVS FIFO commit pointer once done

Commit 9ec03d7f1ed3 ("drm/vc4: kms: Wait on previous FIFO users before a commit") introduced a wait on the previous commit done on a given HVS FIFO.

However, we never cleared that pointer once done. Since drm_crtc_commit_put can free the drm_crtc_commit structure directly if we were the last user, this means that it can lead to a use-after free if we were to duplicate the state, and that stale pointer would even be copied to the new state.

Set the pointer to NULL once we're done with the wait so that we don't carry over a pointer to a free'd structure.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux9ec03d7f1ed394897891319a4dda75f52c5d292d < 2931db9a5ed219546cf2ae0546698faf78281b89affected
LinuxLinux9ec03d7f1ed394897891319a4dda75f52c5d292d < d134c5ff71c7f2320fc7997f2fbbdedf0c76889aaffected
LinuxLinux5.12affected
LinuxLinux0 < 5.12unaffected
LinuxLinux5.15.7 <= 5.15.*unaffected
LinuxLinux5.16 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References