CVE-2024-49854

Summary

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

block, bfq: fix uaf for accessing waker_bfqq after splitting

After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe.

Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxe0c20d88b7dce85d2703bb6ba77bf359959675cd < 63a07379fdb6c72450cb05294461c6016b8b7726affected
LinuxLinuxde6c5e3a456019d2182e345730e59721714fa0b5 < de0456460f2abf921e356ed2bd8da87a376680bdaffected
LinuxLinux19f3bec2ac4be329b9bd12b18a989b867618d2d8 < 0780451f03bf518bc032a7c584de8f92e2d39d7faffected
LinuxLinux13b3d0e8cb121f99b11918a0d4bcc1ce4647d352 < 0b8bda0ff17156cd3f60944527c9d8c9f99f1583affected
LinuxLinux4780f50ea50cfe8e89fc3747bf3dd155488433bb < cae58d19121a70329cf971359e2518c93fec04feaffected
LinuxLinux42c306ed723321af4003b2a41bb73728cab54f85 < 1ba0403ac6447f2d63914fb760c44a3b19c44eafaffected
LinuxLinux9e813033594b141f61ff0ef0cfaaef292564b041affected
LinuxLinux3a5f45a4ad4e1fd36b0a998eef03d76a4f02a2a8affected
LinuxLinux3630a18846c7853aa326d3b42fd0a855af7b41bcaffected
LinuxLinux4.19.323 < 4.20affected
LinuxLinux5.4.285 < 5.5affected
LinuxLinux5.10.227 < 5.11affected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References