Bug 2395242 (CVE-2022-50329)

Summary: CVE-2022-50329 kernel: block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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Description OSIDB Bzimport 2025-09-15 15:02:37 UTC
In the Linux kernel, the following vulnerability has been resolved:

block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq

Commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
will access 'bic->bfqq' in bic_set_bfqq(), however, bfq_exit_icq_bfqq()
can free bfqq first, and then call bic_set_bfqq(), which will cause uaf.

Fix the problem by moving bfq_exit_bfqq() behind bic_set_bfqq().