CVE-2021-47339

Summary

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

media: v4l2-core: explicitly clear ioctl input data

As seen from a recent syzbot bug report, mistakes in the compat ioctl implementation can lead to uninitialized kernel stack data getting used as input for driver ioctl handlers.

The reported bug is now fixed, but it's possible that other related bugs are still present or get added in the future. As the drivers need to check user input already, the possible impact is fairly low, but it might still cause an information leak.

To be on the safe side, always clear the entire ioctl buffer before calling the conversion handler functions that are meant to initialize them.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux8dbcc3fa387c16abfc88a628cf528c439c91b332 < dc02c0b2bd6096f2f3ce63e1fc317aeda05f74d8affected
LinuxLinux8dbcc3fa387c16abfc88a628cf528c439c91b332 < bfb48b54db25c3b4ef4bef5e0691464ebc4aa335affected
LinuxLinux8dbcc3fa387c16abfc88a628cf528c439c91b332 < 7b53cca764f9b291b7907fcd39d9e66ad728ee0baffected
LinuxLinux5.11affected
LinuxLinux0 < 5.11unaffected
LinuxLinux5.12.18 <= 5.12.*unaffected
LinuxLinux5.13.3 <= 5.13.*unaffected
LinuxLinux5.14 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

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

References