In the Linux kernel, the following vulnerability has been resolved:
ext4: Fix function prototype mismatch for ext4_feat_ktype
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed.
ext4_feat_ktype was setting the "release" handler to "kfree", which doesn't have a matching function prototype. Add a simple wrapper with the correct prototype.
This was found as a result of Clang's new -Wcast-function-type-strict flag, which is more sensitive than the simpler -Wcast-function-type, which only checks for type width mismatches.
Note that this code is only reached when ext4 is a loadable module and it is being unloaded:
CFI failure at kobject_put+0xbb/0x1b0 (target: kfree+0x0/0x180; expected type: 0x7c4aa698) ... RIP: 0010:kobject_put+0xbb/0x1b0 ... Call Trace: <TASK> ext4_exit_sysfs+0x14/0x60 [ext4] cleanup_module+0x67/0xedb [ext4]
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Amazon Linux Ami 2 | — | Upgrade kernel-debuginfo-common-x86_64Upgrade kernel-develUpgrade kernel-livepatch-5.10.173-154.642Upgrade kernelUpgrade kernel-tools-develUpgrade kernel-toolsUpgrade bpftoolUpgrade bpftool-debuginfoUpgrade kernel-livepatch-5.15.102-61.139Upgrade kernel-tools-debuginfoUpgrade perf-debuginfoUpgrade kernel-debuginfoUpgrade kernel-headersUpgrade python-perfUpgrade perfUpgrade kernel-debuginfo-common-aarch64Upgrade python-perf-debuginfo | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade kernel-debuginfo-common-x86_64Upgrade kernel-libbpfUpgrade kernel-tools-debuginfoUpgrade kernelUpgrade bpftool-debuginfoUpgrade python3-perf-debuginfoUpgrade kernel-libbpf-develUpgrade bpftoolUpgrade kernel-livepatch-6.1.15-28.43Upgrade kernel-libbpf-staticUpgrade kernel-develUpgrade kernel-headersUpgrade python3-perfUpgrade perf-debuginfoUpgrade kernel-debuginfoUpgrade perfUpgrade kernel-toolsUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-tools-devel | Sep 30, 2025 | Sep 15, 2025 |
| Debian | — | Upgrade linux | Sep 17, 2025 | Sep 17, 2025 |
| Redhat_linux | — | Upgrade kernelNo solution exists | Nov 14, 2025 | Sep 15, 2025 |
| Ubuntu | — | Upgrade linux-gcp-fipsUpgrade linux-gcpUpgrade linux-kvmUpgrade linux-awsUpgrade linux-intel-iot-realtimeUpgrade linux-azure-5.15Upgrade linux-gcp-5.4Upgrade linux-raspi-5.4Upgrade linux-ibmUpgrade linux-iotUpgrade linux-bluefieldUpgrade linux-azure-5.4Upgrade linux-ibm-5.4Upgrade linux-intel-iotg-5.15Upgrade linux-hwe-5.4Upgrade linux-aws-fipsUpgrade linux-lowlatency-hwe-5.15Upgrade linux-realtimeUpgrade linux-gkeUpgrade linux-raspiUpgrade linux-azureUpgrade linux-aws-5.15Upgrade linux-riscv-5.15Upgrade linux-nvidia-tegra-5.15Upgrade linux-oracle-5.4Upgrade linuxUpgrade linux-azure-fipsUpgrade linux-lowlatencyUpgrade linux-intel-iotgUpgrade linux-oracle-5.15Upgrade linux-gkeopUpgrade linux-nvidiaUpgrade linux-hwe-5.15Upgrade linux-xilinx-zynqmpUpgrade linux-aws-5.4Upgrade linux-fipsUpgrade linux-gcp-5.15Upgrade linux-oracle | Sep 19, 2025 | Sep 16, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Oct 15, 2025 | Sep 15, 2025 |
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