CVE-2026-43129ima: verify the previous kernel's IMA buffer lies in addressable RAM

Official description

In the Linux kernel, the following vulnerability has been resolved: ima: verify the previous kernel's IMA buffer lies in addressable RAM Patch series "Address page fault in ima_restore_measurement_list()", v3. When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>" we observe a pafe fault that happens. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) not-present page This happens on x86_64 only, as this is already fixed in aarch64 in commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") This patch (of 3): When the second-stage kernel is booted with a limiting command line (e.g. "mem=<size>"), the IMA measurement buffer handed over from the previous kernel may fall outside the addressable RAM of the new kernel. Accessing such a buffer can fault during early restore. Introduce a small generic helper, ima_validate_range(), which verifies that a physical [start, end] range for the previous-kernel IMA buffer lies within addressable memory: - On x86, use pfn_range_is_mapped(). - On OF based architectures, use page_is_ram().

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/5bfa1941ec40d5bed68f3e3f22ea13aff9c6d67a
• https://git.kernel.org/stable/c/43308106a1762b72f3b20a44b75b2df5cb25b77b
• https://git.kernel.org/stable/c/f11d7d088f5ed54b31c6735854c12845eb60eb4a
• https://git.kernel.org/stable/c/9e1f51c1ad57cc76a0e8b5eb27038f8973fff4fa
• https://git.kernel.org/stable/c/5366ec7d2f793ce703c403d7fd4c25a3db365b9d
• https://git.kernel.org/stable/c/10d1c75ed4382a8e79874379caa2ead8952734f9