The quilt patch titled Subject: kho: only fill kimage if KHO is finalized has been removed from the -mm tree. Its filename was kho-only-fill-kimage-if-kho-is-finalized.patch

This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------ From: Pratyush Yadav pratyush@kernel.org Subject: kho: only fill kimage if KHO is finalized Date: Thu, 18 Sep 2025 19:06:15 +0200

kho_fill_kimage() only checks for KHO being enabled before filling in the FDT to the image. KHO being enabled does not mean that the kernel has data to hand over. That happens when KHO is finalized.

When a kexec is done with KHO enabled but not finalized, the FDT page is allocated but not initialized. FDT initialization happens after finalize. This means the KHO segment is filled in but the FDT contains garbage data.

This leads to the below error messages in the next kernel:

[ 0.000000] KHO: setup: handover FDT (0x10116b000) is invalid: -9 [ 0.000000] KHO: disabling KHO revival: -22

There is no problem in practice, and the next kernel boots and works fine. But this still leads to misleading error messages and garbage being handed over.

Only fill in KHO segment when KHO is finalized. When KHO is not enabled, the debugfs interface is not created and there is no way to finalize it anyway. So the check for kho_enable is not needed, and kho_out.finalize alone is enough.

Link: https://lkml.kernel.org/r/20250918170617.91413-1-pratyush@kernel.org Fixes: 3bdecc3c93f9 ("kexec: add KHO support to kexec file loads") Signed-off-by: Pratyush Yadav pratyush@kernel.org Reviewed-by: Mike Rapoport (Microsoft) rppt@kernel.org Cc: Alexander Graf graf@amazon.com Cc: Baoquan He bhe@redhat.com Cc: Changyuan Lyu changyuanl@google.com Cc: Jason Gunthorpe jgg@nvidia.com Cc: Pasha Tatashin pasha.tatashin@soleen.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

kernel/kexec_handover.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/kexec_handover.c~kho-only-fill-kimage-if-kho-is-finalized +++ a/kernel/kexec_handover.c @@ -1253,7 +1253,7 @@ int kho_fill_kimage(struct kimage *image int err = 0; struct kexec_buf scratch;

- if (!kho_enable) + if (!kho_out.finalized) return 0;

image->kho.fdt = page_to_phys(kho_out.ser.fdt); _

Patches currently in -mm which might be from pratyush@kernel.org are

kho-add-support-for-preserving-vmalloc-allocations-fix.patch