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| author | Joerg Roedel <jroedel@suse.de> | 2020-10-28 17:46:57 +0100 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-10-29 18:06:52 +0100 |
| commit | 86ce43f7dde81562f58b24b426cef068bd9f7595 (patch) | |
| tree | f3042a795cff8aa037faa8c7d77e61d003af12d7 /arch/x86/boot | |
| parent | ed7b895f3efb5df184722f5a30f8164fcaffceb1 (diff) | |
| download | linux-86ce43f7dde81562f58b24b426cef068bd9f7595.tar.bz2 | |
x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path
Check whether the hypervisor reported the correct C-bit when running as
an SEV guest. Using a wrong C-bit position could be used to leak
sensitive data from the guest to the hypervisor.
The check function is in a separate file:
arch/x86/kernel/sev_verify_cbit.S
so that it can be re-used in the running kernel image.
[ bp: Massage. ]
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lkml.kernel.org/r/20201028164659.27002-4-joro@8bytes.org
Diffstat (limited to 'arch/x86/boot')
| -rw-r--r-- | arch/x86/boot/compressed/ident_map_64.c | 1 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/mem_encrypt.S | 4 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/misc.h | 2 |
3 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index a5e5db6ada3c..39b2eded7bc2 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -164,6 +164,7 @@ void initialize_identity_maps(void *rmode) add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE); /* Load the new page-table. */ + sev_verify_cbit(top_level_pgt); write_cr3(top_level_pgt); } diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S index 3092ae173f94..aa561795efd1 100644 --- a/arch/x86/boot/compressed/mem_encrypt.S +++ b/arch/x86/boot/compressed/mem_encrypt.S @@ -68,6 +68,9 @@ SYM_FUNC_START(get_sev_encryption_bit) SYM_FUNC_END(get_sev_encryption_bit) .code64 + +#include "../../kernel/sev_verify_cbit.S" + SYM_FUNC_START(set_sev_encryption_mask) #ifdef CONFIG_AMD_MEM_ENCRYPT push %rbp @@ -111,4 +114,5 @@ SYM_FUNC_END(set_sev_encryption_mask) .balign 8 SYM_DATA(sme_me_mask, .quad 0) SYM_DATA(sev_status, .quad 0) +SYM_DATA(sev_check_data, .quad 0) #endif diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 6d31f1b4c4d1..d9a631c5973c 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -159,4 +159,6 @@ void boot_page_fault(void); void boot_stage1_vc(void); void boot_stage2_vc(void); +unsigned long sev_verify_cbit(unsigned long cr3); + #endif /* BOOT_COMPRESSED_MISC_H */ |