kernel.git/arch/x86/boot/compressed, branch linux-5.12.y

x86/boot/compressed/64: Check SEV encryption in the 32-bit boot-path

2021-05-26T10:59:14Z

commit fef81c86262879d4b1176ef51a834c15b805ebb9 upstream. 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. Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210312123824.306-8-joro@8bytes.org Signed-off-by: Greg Kroah-Hartman

x86/boot: Add $(CLANG_FLAGS) to compressed KBUILD_CFLAGS

2021-05-12T06:39:35Z

[ Upstream commit d5cbd80e302dfea59726c44c56ab7957f822409f ] When cross compiling x86 on an ARM machine with clang, there are several errors along the lines of: arch/x86/include/asm/string_64.h:27:10: error: invalid output constraint '=&c' in asm This happens because the compressed boot Makefile reassigns KBUILD_CFLAGS and drops the clang flags that set the target architecture ('--target=') and the path to the GNU cross tools ('--prefix='), meaning that the host architecture is targeted. These flags are available as $(CLANG_FLAGS) from the main Makefile so add them to the compressed boot folder's KBUILD_CFLAGS so that cross compiling works as expected. Signed-off-by: Nathan Chancellor Signed-off-by: Borislav Petkov Acked-by: Ard Biesheuvel Link: https://lkml.kernel.org/r/20210326000435.4785-3-nathan@kernel.org Signed-off-by: Sasha Levin

x86/sev: Do not require Hypervisor CPUID bit for SEV guests

2021-05-12T06:39:34Z

[ Upstream commit eab696d8e8b9c9d600be6fad8dd8dfdfaca6ca7c ] A malicious hypervisor could disable the CPUID intercept for an SEV or SEV-ES guest and trick it into the no-SEV boot path, where it could potentially reveal secrets. This is not an issue for SEV-SNP guests, as the CPUID intercept can't be disabled for those. Remove the Hypervisor CPUID bit check from the SEV detection code to protect against this kind of attack and add a Hypervisor bit equals zero check to the SME detection path to prevent non-encrypted guests from trying to enable SME. This handles the following cases: 1) SEV(-ES) guest where CPUID intercept is disabled. The guest will still see leaf 0x8000001f and the SEV bit. It can retrieve the C-bit and boot normally. 2) Non-encrypted guests with intercepted CPUID will check the SEV_STATUS MSR and find it 0 and will try to enable SME. This will fail when the guest finds MSR_K8_SYSCFG to be zero, as it is emulated by KVM. But we can't rely on that, as there might be other hypervisors which return this MSR with bit 23 set. The Hypervisor bit check will prevent that the guest tries to enable SME in this case. 3) Non-encrypted guests on SEV capable hosts with CPUID intercept disabled (by a malicious hypervisor) will try to boot into the SME path. This will fail, but it is also not considered a problem because non-encrypted guests have no protection against the hypervisor anyway. [ bp: s/non-SEV/non-encrypted/g ] Signed-off-by: Joerg Roedel Signed-off-by: Borislav Petkov Acked-by: Tom Lendacky Link: https://lkml.kernel.org/r/20210312123824.306-3-joro@8bytes.org Signed-off-by: Sasha Levin

Merge tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-12-24T20:40:07Z

Pull EFI updates from Borislav Petkov: "These got delayed due to a last minute ia64 build issue which got fixed in the meantime. EFI updates collected by Ard Biesheuvel: - Don't move BSS section around pointlessly in the x86 decompressor - Refactor helper for discovering the EFI secure boot mode - Wire up EFI secure boot to IMA for arm64 - Some fixes for the capsule loader - Expose the RT_PROP table via the EFI test module - Relax DT and kernel placement restrictions on ARM with a few followup fixes: - fix the build breakage on IA64 caused by recent capsule loader changes - suppress a type mismatch build warning in the expansion of EFI_PHYS_ALIGN on ARM" * tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: arm: force use of unsigned type for EFI_PHYS_ALIGN efi: ia64: disable the capsule loader efi: stub: get rid of efi_get_max_fdt_addr() efi/efi_test: read RuntimeServicesSupported efi: arm: reduce minimum alignment of uncompressed kernel efi: capsule: clean scatter-gather entries from the D-cache efi: capsule: use atomic kmap for transient sglist mappings efi: x86/xen: switch to efi_get_secureboot_mode helper arm64/ima: add ima_arch support ima: generalize x86/EFI arch glue for other EFI architectures efi: generalize efi_get_secureboot efi/libstub: EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER should not default to yes efi/x86: Only copy the compressed kernel image in efi_relocate_kernel() efi/libstub/x86: simplify efi_is_native()

kasan, x86, s390: update undef CONFIG_KASAN

2020-12-22T20:55:08Z

With the intoduction of hardware tag-based KASAN some kernel checks of this kind: ifdef CONFIG_KASAN will be updated to: if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) x86 and s390 use a trick to #undef CONFIG_KASAN for some of the code that isn't linked with KASAN runtime and shouldn't have any KASAN annotations. Also #undef CONFIG_KASAN_GENERIC with CONFIG_KASAN. Link: https://lkml.kernel.org/r/9d84bfaaf8fabe0fc89f913c9e420a30bd31a260.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Signed-off-by: Vincenzo Frascino Reviewed-by: Marco Elver Acked-by: Vasily Gorbik Reviewed-by: Alexander Potapenko Tested-by: Vincenzo Frascino Cc: Andrey Ryabinin Cc: Branislav Rankov Cc: Catalin Marinas Cc: Dmitry Vyukov Cc: Evgenii Stepanov Cc: Kevin Brodsky Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-12-14T21:45:26Z

Pull x86 cleanups from Borislav Petkov: "Another branch with a nicely negative diffstat, just the way I like 'em: - Remove all uses of TIF_IA32 and TIF_X32 and reclaim the two bits in the end (Gabriel Krisman Bertazi) - All kinds of minor cleanups all over the tree" * tag 'x86_cleanups_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) x86/ia32_signal: Propagate __user annotation properly x86/alternative: Update text_poke_bp() kernel-doc comment x86/PCI: Make a kernel-doc comment a normal one x86/asm: Drop unused RDPID macro x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg x86/head64: Remove duplicate include x86/mm: Declare 'start' variable where it is used x86/head/64: Remove unused GET_CR2_INTO() macro x86/boot: Remove unused finalize_identity_maps() x86/uaccess: Document copy_from_user_nmi() x86/dumpstack: Make show_trace_log_lvl() static x86/mtrr: Fix a kernel-doc markup x86/setup: Remove unused MCA variables x86, libnvdimm/test: Remove COPY_MC_TEST x86: Reclaim TIF_IA32 and TIF_X32 x86/mm: Convert mmu context ia32_compat into a proper flags field x86/elf: Use e_machine to check for x32/ia32 in setup_additional_pages() elf: Expose ELF header on arch_setup_additional_pages() x86/elf: Use e_machine to select start_thread for x32 elf: Expose ELF header in compat_start_thread() ...

Merge tag 'x86-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-12-06T19:22:39Z

Pull x86 fixes from Thomas Gleixner: "A set of fixes for x86: - Make the AMD L3 QoS code and data priorization enable/disable mechanism work correctly. The control bit was only set/cleared on one of the CPUs in a L3 domain, but it has to be modified on all CPUs in the domain. The initial documentation was not clear about this, but the updated one from Oct 2020 spells it out. - Fix an off by one in the UV platform detection code which causes the UV hubs to be identified wrongly. The chip revisions start at 1 not at 0. - Fix a long standing bug in the evaluation of prefixes in the uprobes code which fails to handle repeated prefixes properly. The aggregate size of the prefixes can be larger than the bytes array but the code blindly iterated over the aggregate size beyond the array boundary. Add a macro to handle this case properly and use it at the affected places" * tag 'x86-urgent-2020-12-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev-es: Use new for_each_insn_prefix() macro to loop over prefixes bytes x86/insn-eval: Use new for_each_insn_prefix() macro to loop over prefixes bytes x86/uprobes: Do not use prefixes.nbytes when looping over prefixes.bytes x86/platform/uv: Fix UV4 hub revision adjustment x86/resctrl: Fix AMD L3 QOS CDP enable/disable

x86/sev-es: Use new for_each_insn_prefix() macro to loop over prefixes bytes

2020-12-06T09:03:08Z

Since insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a prefix is repeated, the proper check must be: insn.prefixes.bytes[i] != 0 and i < 4 instead of using insn.prefixes.nbytes. Use the new for_each_insn_prefix() macro which does it correctly. Debugged by Kees Cook . [ bp: Massage commit message. ] Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions") Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com Signed-off-by: Masami Hiramatsu Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/160697106089.3146288.2052422845039649176.stgit@devnote2

kbuild: Hoist '--orphan-handling' into Kconfig

2020-12-01T13:45:36Z

Currently, '--orphan-handling=warn' is spread out across four different architectures in their respective Makefiles, which makes it a little unruly to deal with in case it needs to be disabled for a specific linker version (in this case, ld.lld 10.0.1). To make it easier to control this, hoist this warning into Kconfig and the main Makefile so that disabling it is simpler, as the warning will only be enabled in a couple places (main Makefile and a couple of compressed boot folders that blow away LDFLAGS_vmlinx) and making it conditional is easier due to Kconfig syntax. One small additional benefit of this is saving a call to ld-option on incremental builds because we will have already evaluated it for CONFIG_LD_ORPHAN_WARN. To keep the list of supported architectures the same, introduce CONFIG_ARCH_WANT_LD_ORPHAN_WARN, which an architecture can select to gain this automatically after all of the sections are specified and size asserted. A special thanks to Kees Cook for the help text on this config. Link: https://github.com/ClangBuiltLinux/linux/issues/1187 Acked-by: Kees Cook Acked-by: Michael Ellerman (powerpc) Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Signed-off-by: Nathan Chancellor Signed-off-by: Masahiro Yamada

x86/boot/compressed/64: Use TEST %reg,%reg instead of CMP $0,%reg

2020-11-21T09:26:25Z

Use TEST %reg,%reg which sets the zero flag in the same way as CMP $0,%reg, but the encoding uses one byte less. Signed-off-by: Uros Bizjak Signed-off-by: Borislav Petkov Reviewed-by: Andy Lutomirski Link: https://lkml.kernel.org/r/20201029160258.139216-1-ubizjak@gmail.com