In the Linux kernel, the following vulnerability has been resolved:
fprobe: Fix unregister_fprobe() to wait for RCU grace period
Commit 4346ba1604093 ("fprobe: Rewrite fprobe on function-graph tracer") changed fprobe to register struct fprobe to an rcu-hlist, but it forgot to wait for RCU GP. Thus there can be use-after-free if the fprobe is released right after unregistering. This can be happened on fprobe event and sample module code.
To fix this issue, add synchronize_rcu() in unregister_fprobe().
Note that BPF is OK because fprobe is used as a part of bpf_kprobe_multi_link. This unregisters its fprobe in bpf_kprobe_multi_link_release() and it is deallocated via bpf_kprobe_multi_link_dealloc(), which is invoked from bpf_link_defer_dealloc_rcu_gp() RCU callback.
For BPF, this also introduced unregister_fprobe_async() which does NOT wait for RCU grace priod.
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon_linux_2023 | — | Upgrade kernel6.18-headersUpgrade kernel6.18Upgrade kernel6.18-debuginfo-common-aarch64Upgrade microvm-kernel6.18Upgrade kernel6.18-develUpgrade kernel6.18-tools-develUpgrade kernel6.18-toolsUpgrade kernel6.18-modules-extra-commonUpgrade kernel6.18-modules-extraUpgrade bpftool6.18-debuginfoUpgrade kernel6.18-tools-debuginfoUpgrade perf6.18-debuginfoUpgrade python3-perf6.18-debuginfoUpgrade perf6.18Upgrade python3-perf6.18Upgrade kernel-livepatch-6.18.35-68.127Upgrade bpftool6.18Upgrade kernel6.18-debuginfo-common-x86_64Upgrade kernel6.18-debuginfo | Sep 7, 2026 | Jul 19, 2026 |
| Redhat_linux | — | — | Jul 22, 2026 | Jul 19, 2026 |
| Ubuntu | — | Upgrade linux-image-azureUpgrade linux-image-azure-fdeUpgrade linux-image-nvidia-bos-7.0Upgrade linux-image-7.0.0-1011-gcp-64kUpgrade linux-image-7.0.0-1011-gcpUpgrade linux-image-7.0.0-1009-aws-64kUpgrade linux-image-azure-fde-7.0Upgrade linux-image-oracle-64k-7.0Upgrade linux-image-nvidia-64k-hwe-26.04Upgrade linux-image-7.0.0-1010-ibmUpgrade linux-image-gcp-7.0Upgrade linux-image-ibmUpgrade linux-image-7.0.0-2016-nvidia-bos-64kUpgrade linux-image-nvidiaUpgrade linux-image-raspi-realtime-7.0Upgrade linux-image-7.0.0-1009-azure-fdeUpgrade linux-image-aws-7.0Upgrade linux-image-nvidia-bos-64k-7.0Upgrade linux-image-7.0.0-1008-oracle-64kUpgrade linux-image-aws-64kUpgrade linux-image-nvidia-7.0Upgrade linux-image-oracle-7.0Upgrade linux-image-ibm-7.0Upgrade linux-image-nvidia-64k-7.0Upgrade linux-image-7.0.0-2016-nvidia-bosUpgrade linux-image-7.0.0-1009-awsUpgrade linux-image-7.0.0-1010-azureUpgrade linux-image-aws-64k-7.0Upgrade linux-image-nvidia-hwe-26.04Upgrade linux-image-oracleUpgrade linux-image-7.0.0-1016-nvidiaUpgrade linux-image-azure-7.0Upgrade linux-image-awsUpgrade linux-image-raspi-7.0Upgrade linux-image-gcp-64kUpgrade linux-image-7.0.0-1015-raspi-realtimeUpgrade linux-image-oracle-64kUpgrade linux-image-nvidia-bos-64kUpgrade linux-image-7.0.0-1011-oracle-64kUpgrade linux-image-7.0.0-1008-oracleUpgrade linux-image-7.0.0-1015-raspiUpgrade linux-image-7.0.0-1014-azureUpgrade linux-image-nvidia-bosUpgrade linux-image-7.0.0-1011-oracleUpgrade linux-image-raspiUpgrade linux-image-7.0.0-1016-nvidia-64kUpgrade linux-image-gcp-64k-7.0Upgrade linux-image-raspi-realtimeUpgrade linux-image-nvidia-64kUpgrade linux-image-gcp | Jul 21, 2026 | Jul 20, 2026 |
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