🛡️ CVE-2021-47318 on Ubuntu — linux-allwinner-5.19
Description
In the Linux kernel, the following vulnerability has been resolved: arch_topology: Avoid use-after-free for scale_freq_data Currently topology_scale_freq_tick() (which gets called from scheduler_tick()) may end up using a pointer to "struct scale_freq_data", which was previously cleared by topology_clear_scale_freq_source(), as there is no protection in place here. The users of topology_clear_scale_freq_source() though needs a guarantee that the previously cleared scale_freq_data isn't used anymore, so they can free the related resources. Since topology_scale_freq_tick() is called from scheduler tick, we don't want to add locking in there. Use the RCU update mechanism instead (which is already used by the scheduler's utilization update path) to guarantee race free updates here. synchronize_rcu() makes sure that all RCU critical sections that started before it is called, will finish before it returns. And so the callers of topology_clear_scale_freq_source() don't need to worry about their callback getting called anymore.
Distribution advisory
This page covers CVE-2021-47318 as tracked by Ubuntu, for the package linux-allwinner-5.19. No fixed version has been recorded for this distribution yet.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.
Affected software and timeline
Affected software: linux-allwinner-5.19, linux-aws-5.0, linux-aws-5.11, linux-aws-5.13, linux-aws-5.19, linux-aws-5.3, linux-aws-5.8, linux-aws-6.2, linux-azure, linux-azure-5.11, linux-azure-5.13, linux-azure-5.19, linux-azure-5.3, linux-azure-5.8, linux-azure-6.2, linux-azure-edge, linux-azure-fde, linux-azure-fde-5.19, linux-azure-fde-6.2, linux-gcp, linux-gcp-5.11, linux-gcp-5.13, linux-gcp-5.19, linux-gcp-5.3, linux-gcp-5.8, linux-gcp-6.2, linux-gke, linux-gke-4.15, linux-gke-5.15, linux-gke-5.4, linux-gkeop-5.4, linux-hwe, linux-hwe-5.11, linux-hwe-5.13, linux-hwe-5.19, linux-hwe-5.8, linux-hwe-6.2, linux-hwe-edge, linux-intel-5.13, linux-lowlatency-hwe-5.19, linux-lowlatency-hwe-6.2, linux-nvidia-6.2, linux-oem, linux-oem-5.10, linux-oem-5.13, linux-oem-5.14, linux-oem-5.17, linux-oem-5.6, linux-oem-6.0, linux-oem-6.1, linux-oracle-5.0, linux-oracle-5.11, linux-oracle-5.13, linux-oracle-5.3, linux-oracle-5.8, linux-raspi2, linux-riscv, linux-riscv-5.11, linux-riscv-5.19, linux-riscv-5.8, linux-starfive-5.19 and linux-starfive-6.2. Published on 21 May 2024 and last revised on 24 October 2025. No public exploit is currently recorded for this entry. Record sourced from OSV.
CVE-2021-47318 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| linux-allwinner-5.19 | — | — |
| linux-aws-5.0 | — | — |
| linux-aws-5.11 | — | — |
| linux-aws-5.13 | — | — |
| linux-aws-5.19 | — | — |
| linux-aws-5.3 | — | — |
| linux-aws-5.8 | — | — |
| linux-aws-6.2 | — | — |
| linux-azure | — | — |
| linux-azure-5.11 | — | — |
| linux-azure-5.13 | — | — |
| linux-azure-5.19 | — | — |
| linux-azure-5.3 | — | — |
| linux-azure-5.8 | — | — |
| linux-azure-6.2 | — | — |
| linux-azure-edge | — | — |
| linux-azure-fde | — | — |
| linux-azure-fde-5.19 | — | — |
| linux-azure-fde-6.2 | — | — |
| linux-gcp | — | — |
| linux-gcp-5.11 | — | — |
| linux-gcp-5.13 | — | — |
| linux-gcp-5.19 | — | — |
| linux-gcp-5.3 | — | — |
| linux-gcp-5.8 | — | — |
| linux-gcp-6.2 | — | — |
| linux-gke | — | — |
| linux-gke-4.15 | — | — |
| linux-gke-5.15 | — | — |
| linux-gke-5.4 | — | — |
| linux-gkeop-5.4 | — | — |
| linux-hwe | — | — |
| linux-hwe-5.11 | — | — |
| linux-hwe-5.13 | — | — |
| linux-hwe-5.19 | — | — |
| linux-hwe-5.8 | — | — |
| linux-hwe-6.2 | — | — |
| linux-hwe-edge | — | — |
| linux-intel-5.13 | — | — |
| linux-lowlatency-hwe-5.19 | — | — |
| linux-lowlatency-hwe-6.2 | — | — |
| linux-nvidia-6.2 | — | — |
| linux-oem | — | — |
| linux-oem-5.10 | — | — |
| linux-oem-5.13 | — | — |
| linux-oem-5.14 | — | — |
| linux-oem-5.17 | — | — |
| linux-oem-5.6 | — | — |
| linux-oem-6.0 | — | — |
| linux-oem-6.1 | — | — |
| linux-oracle-5.0 | — | — |
| linux-oracle-5.11 | — | — |
| linux-oracle-5.13 | — | — |
| linux-oracle-5.3 | — | — |
| linux-oracle-5.8 | — | — |
| linux-raspi2 | — | — |
| linux-riscv | — | — |
| linux-riscv-5.11 | — | — |
| linux-riscv-5.19 | — | — |
| linux-riscv-5.8 | — | — |
| linux-starfive-5.19 | — | — |
| linux-starfive-6.2 | — | — |
References
Similar Threats
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