diff options
| author | Coiby Xu <coxu@redhat.com> | 2025-05-02 04:12:42 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-05-21 20:48:22 +0300 |
| commit | cc66e4863ac3a00c709bfcbec685d48c184172b5 (patch) | |
| tree | 759f859cdbb298009d63916d4c203d047774f550 | |
| parent | 5eb3f60554216b02e9c0f18356709ee4befe72e7 (diff) | |
| download | linux-cc66e4863ac3a00c709bfcbec685d48c184172b5.tar.xz | |
x86/crash: make the page that stores the dm crypt keys inaccessible
This adds an addition layer of protection for the saved copy of dm crypt
key. Trying to access the saved copy will cause page fault.
Link: https://lkml.kernel.org/r/20250502011246.99238-9-coxu@redhat.com
Signed-off-by: Coiby Xu <coxu@redhat.com>
Suggested-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: Milan Broz <gmazyland@gmail.com>
Cc: Ondrej Kozina <okozina@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | arch/x86/kernel/machine_kexec_64.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index a68f5a0a9f37..f615fcb6d35d 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -598,13 +598,35 @@ static void kexec_mark_crashkres(bool protect) kexec_mark_range(control, crashk_res.end, protect); } +/* make the memory storing dm crypt keys in/accessible */ +static void kexec_mark_dm_crypt_keys(bool protect) +{ + unsigned long start_paddr, end_paddr; + unsigned int nr_pages; + + if (kexec_crash_image->dm_crypt_keys_addr) { + start_paddr = kexec_crash_image->dm_crypt_keys_addr; + end_paddr = start_paddr + kexec_crash_image->dm_crypt_keys_sz - 1; + nr_pages = (PAGE_ALIGN(end_paddr) - PAGE_ALIGN_DOWN(start_paddr))/PAGE_SIZE; + if (protect) + set_memory_np((unsigned long)phys_to_virt(start_paddr), nr_pages); + else + __set_memory_prot( + (unsigned long)phys_to_virt(start_paddr), + nr_pages, + __pgprot(_PAGE_PRESENT | _PAGE_NX | _PAGE_RW)); + } +} + void arch_kexec_protect_crashkres(void) { kexec_mark_crashkres(true); + kexec_mark_dm_crypt_keys(true); } void arch_kexec_unprotect_crashkres(void) { + kexec_mark_dm_crypt_keys(false); kexec_mark_crashkres(false); } #endif |