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 perf-debuginfoUpgrade kernel-livepatch-5.15.102-61.139Upgrade kernel-tools-debuginfoUpgrade python-perf-debuginfoUpgrade bpftool-debuginfoUpgrade perfUpgrade python-perfUpgrade kernel-headersUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-debuginfoUpgrade kernel-develUpgrade kernelUpgrade kernel-toolsUpgrade bpftoolUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-livepatch-5.10.173-154.642Upgrade kernel-tools-devel | May 20, 2026 | May 20, 2026 |
| Amazon_linux_2023 | — | Upgrade perfUpgrade kernel-debuginfo-common-aarch64Upgrade kernel-develUpgrade python3-perfUpgrade perf-debuginfoUpgrade kernel-headersUpgrade kernel-debuginfoUpgrade kernel-tools-develUpgrade kernel-toolsUpgrade bpftool-debuginfoUpgrade kernel-tools-debuginfoUpgrade python3-perf-debuginfoUpgrade kernel-debuginfo-common-x86_64Upgrade kernel-libbpf-develUpgrade kernel-livepatch-6.1.15-28.43Upgrade kernelUpgrade bpftoolUpgrade kernel-libbpf-staticUpgrade kernel-libbpf | 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-raspiUpgrade linux-azureUpgrade linux-nvidia-tegra-5.15Upgrade linux-azure-fipsUpgrade linux-gkeUpgrade linux-gcp-5.15Upgrade linux-fipsUpgrade linux-realtimeUpgrade linux-hwe-5.15Upgrade linux-nvidiaUpgrade linux-aws-5.15Upgrade linux-oracleUpgrade linux-gkeopUpgrade linux-xilinx-zynqmpUpgrade linux-aws-5.4Upgrade linux-lowlatency-hwe-5.15Upgrade linux-intel-iotgUpgrade linux-lowlatencyUpgrade linuxUpgrade linux-riscv-5.15Upgrade linux-oracle-5.4Upgrade linux-oracle-5.15Upgrade linux-raspi-5.4Upgrade linux-bluefieldUpgrade linux-azure-5.4Upgrade linux-azure-5.15Upgrade linux-gcp-5.4Upgrade linux-iotUpgrade linux-ibm-5.4Upgrade linux-ibmUpgrade linux-kvmUpgrade linux-awsUpgrade linux-gcpUpgrade linux-intel-iot-realtimeUpgrade linux-gcp-fipsUpgrade linux-intel-iotg-5.15Upgrade linux-aws-fipsUpgrade linux-hwe-5.4 | 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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