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