[Cc: Roberto Sassu, linux-integrity] On Tue, 2025-12-02 at 08:16 +0100, Ard Biesheuvel wrote: > On Mon, 1 Dec 2025 at 22:43, Mimi Zohar <[email protected]> wrote: > > > > On Mon, 2025-12-01 at 15:03 +0530, Harshit Mogalapalli wrote: > > > Hi all, > > > > > > On 13/11/25 01:00, Harshit Mogalapalli wrote: > > > > When the second-stage kernel is booted via kexec with a limiting command > > > > line such as "mem=<size>", 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. > > > > It should be obvious that without carrying the measurement list across > > kexec, > > that attestation will fail. Please mention it here in the patch > > description. > > > > Couldn't we just use memremap() and be done with it? That will use the > direct map if the memory is mapped, or vmap() it otherwise.
No, the IMA measurement list is not a continuous buffer, but a linked list of records with varying types of fields and field sizes. The call to ima_dump_measurement_list() marshals the measurement list into a buffer, while ima_restore_measurement_list() unmarshals it. -- thanks, Mimi
