From c5489d04337b47e93c0623e8145fcba3f5739efd Mon Sep 17 00:00:00 2001 From: Harshit Mogalapalli Date: Tue, 30 Dec 2025 22:16:09 -0800 Subject: [PATCH] x86/kexec: add a sanity check on previous kernel's ima kexec buffer MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit When the second-stage kernel is booted via kexec with a limiting command line such as "mem=", the physical range that contains the carried over IMA measurement list may fall outside the truncated RAM leading to a kernel panic. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) – not-present page Other architectures already validate the range with page_is_ram(), as done in commit cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") do a similar check on x86. Without carrying the measurement list across kexec, the attestation would fail. Link: https://lkml.kernel.org/r/20251231061609.907170-4-harshit.m.mogalapalli@oracle.com Signed-off-by: Harshit Mogalapalli Fixes: b69a2afd5afc ("x86/kexec: Carry forward IMA measurement log on kexec") Reported-by: Paul Webb Reviewed-by: Mimi Zohar Cc: Alexander Graf Cc: Ard Biesheuvel Cc: Baoquan He Cc: Borislav Betkov Cc: guoweikang Cc: Henry Willard Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jiri Bohac Cc: Joel Granados Cc: Jonathan McDowell Cc: Mike Rapoport Cc: Sohil Mehta Cc: Sourabh Jain Cc: Thomas Gleinxer Cc: Yifei Liu Cc: Signed-off-by: Andrew Morton --- arch/x86/kernel/setup.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 1b2edd07a3e17..383d4a4784f5b 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -439,9 +439,15 @@ int __init ima_free_kexec_buffer(void) int __init ima_get_kexec_buffer(void **addr, size_t *size) { + int ret; + if (!ima_kexec_buffer_size) return -ENOENT; + ret = ima_validate_range(ima_kexec_buffer_phys, ima_kexec_buffer_size); + if (ret) + return ret; + *addr = __va(ima_kexec_buffer_phys); *size = ima_kexec_buffer_size; -- 2.47.3