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