CVE-2023-54107
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: dropping parent refcount after pd_free_fn() is done Some cgroup policies will access parent pd through child pd even after pd_offline_fn() is done. If pd_free_fn() for parent is called before child, then UAF can be triggered. Hence it's better to guarantee the order of pd_free_fn(). Currently refcount of parent blkg is dropped in __blkg_release(), which is before pd_free_fn() is called in blkg_free_work_fn() while blkg_free_work_fn() is called asynchronously. This patch make sure pd_free_fn() called from removing cgroup is ordered by delaying dropping parent refcount after calling pd_free_fn() for child. BTW, pd_free_fn() will also be called from blkcg_deactivate_policy() from deleting device, and following patches will guarantee the order.
Affected versions
Linux kernel versions
5.18
and later are affected. Fixed in
6.3
and their respective stable series.
References
1 totalFrequently asked questions
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What is CVE-2023-54107?
CVE-2023-54107 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18 onward and has been patched in 6.3. CVE-2023-54107 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2023-54107?
Yes. CVE-2023-54107 has been patched. Fixed versions include 6.3. If you are running Linux kernel 5.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2023-54107 actively exploited?
No. CVE-2023-54107 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.