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