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-livepatch-5.10.173-154.642Upgrade kernel-debuginfo-common-x86_64Upgrade kernelUpgrade kernel-tools-develUpgrade kernel-toolsUpgrade bpftoolUpgrade kernel-develUpgrade bpftool-debuginfoUpgrade kernel-livepatch-5.15.102-61.139Upgrade kernel-headersUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-tools-debuginfoUpgrade perf-debuginfoUpgrade perfUpgrade python-perf-debuginfoUpgrade python-perfUpgrade kernel-debuginfo | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade kernel-libbpf-staticUpgrade bpftoolUpgrade kernel-libbpfUpgrade kernel-tools-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade bpftool-debuginfoUpgrade kernel-libbpf-develUpgrade python3-perf-debuginfoUpgrade kernel-livepatch-6.1.15-28.43Upgrade kernelUpgrade python3-perfUpgrade perfUpgrade kernel-tools-develUpgrade perf-debuginfoUpgrade kernel-toolsUpgrade kernel-debuginfoUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-headersUpgrade kernel-devel | Sep 30, 2025 | Sep 15, 2025 |
| Debian | — | Upgrade linux | Sep 17, 2025 | Sep 17, 2025 |
| Redhat_linux | — | No solution existsUpgrade kernel | Nov 14, 2025 | Sep 15, 2025 |
| Ubuntu | — | Upgrade linux-gkeopUpgrade linux-azure-fipsUpgrade linux-realtimeUpgrade linux-lowlatencyUpgrade linux-oracleUpgrade linux-aws-5.4Upgrade linux-azureUpgrade linux-oracle-5.4Upgrade linux-fipsUpgrade linux-raspiUpgrade linux-gkeUpgrade linux-aws-5.15Upgrade linux-gcp-5.15Upgrade linux-oracle-5.15Upgrade linux-lowlatency-hwe-5.15Upgrade linux-xilinx-zynqmpUpgrade linuxUpgrade linux-nvidiaUpgrade linux-intel-iotgUpgrade linux-hwe-5.15Upgrade linux-riscv-5.15Upgrade linux-nvidia-tegra-5.15Upgrade linux-gcp-fipsUpgrade linux-ibm-5.4Upgrade linux-bluefieldUpgrade linux-intel-iot-realtimeUpgrade linux-gcpUpgrade linux-awsUpgrade linux-intel-iotg-5.15Upgrade linux-aws-fipsUpgrade linux-azure-5.4Upgrade linux-iotUpgrade linux-kvmUpgrade linux-hwe-5.4Upgrade linux-ibmUpgrade linux-raspi-5.4Upgrade linux-gcp-5.4Upgrade linux-azure-5.15 | 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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