linux-stable.git/arch/x86/kernel/cpu/microcode/amd.c, branch linux-6.6.y Linux kernel stable tree x86/microcode/AMD: Select which microcode patch to load 2026-01-17T15:30:00+00:00 Borislav Petkov (AMD) bp@alien8.de 2026-01-12T11:27:48+00:00 5c7c4131beade68a52dacfc7d7fede833a396837 Commit 8d171045069c804e5ffaa18be590c42c6af0cf3f upstream. All microcode patches up to the proper BIOS Entrysign fix are loaded only after the sha256 signature carried in the driver has been verified. Microcode patches after the Entrysign fix has been applied, do not need that signature verification anymore. In order to not abandon machines which haven't received the BIOS update yet, add the capability to select which microcode patch to load. The corresponding microcode container supplied through firmware-linux has been modified to carry two patches per CPU type (family/model/stepping) so that the proper one gets selected. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Tested-by: Waiman Long <longman@redhat.com> Link: https://patch.msgid.link/20251027133818.4363-1-bp@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit 8d171045069c804e5ffaa18be590c42c6af0cf3f upstream.

All microcode patches up to the proper BIOS Entrysign fix are loaded
only after the sha256 signature carried in the driver has been verified.

Microcode patches after the Entrysign fix has been applied, do not need
that signature verification anymore.

In order to not abandon machines which haven't received the BIOS update
yet, add the capability to select which microcode patch to load.

The corresponding microcode container supplied through firmware-linux
has been modified to carry two patches per CPU type
(family/model/stepping) so that the proper one gets selected.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Waiman Long <longman@redhat.com>
Link: https://patch.msgid.link/20251027133818.4363-1-bp@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode/AMD: Fix Entrysign revision check for Zen5/Strix Halo 2026-01-11T14:22:17+00:00 Rong Zhang i@rong.moe 2025-12-29T18:22:21+00:00 45b44c3a5e6246fad08383366413533c2228982d commit 150b1b97e27513535dcd3795d5ecd28e61b6cb8c upstream. Zen5 also contains family 1Ah, models 70h-7Fh, which are mistakenly missing from cpu_has_entrysign(). Add the missing range. Fixes: 8a9fb5129e8e ("x86/microcode/AMD: Limit Entrysign signature checking to known generations") Signed-off-by: Rong Zhang <i@rong.moe> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: stable@kernel.org Link: https://patch.msgid.link/20251229182245.152747-1-i@rong.moe Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 150b1b97e27513535dcd3795d5ecd28e61b6cb8c upstream.

Zen5 also contains family 1Ah, models 70h-7Fh, which are mistakenly missing
from cpu_has_entrysign(). Add the missing range.

Fixes: 8a9fb5129e8e ("x86/microcode/AMD: Limit Entrysign signature checking to known generations")
Signed-off-by: Rong Zhang <i@rong.moe>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: stable@kernel.org
Link: https://patch.msgid.link/20251229182245.152747-1-i@rong.moe
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode/AMD: Limit Entrysign signature checking to known generations 2025-12-01T10:41:49+00:00 Borislav Petkov (AMD) bp@alien8.de 2025-10-23T12:46:29+00:00 3ab328a0258fd51c348205efbd77f076a60bd75f [ Upstream commit 8a9fb5129e8e64d24543ebc70de941a2d77a9e77 ] Limit Entrysign sha256 signature checking to CPUs in the range Zen1-Zen5. X86_BUG cannot be used here because the loading on the BSP happens way too early, before the cpufeatures machinery has been set up. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/all/20251023124629.5385-1-bp@kernel.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 8a9fb5129e8e64d24543ebc70de941a2d77a9e77 ]

Limit Entrysign sha256 signature checking to CPUs in the range Zen1-Zen5.

X86_BUG cannot be used here because the loading on the BSP happens way
too early, before the cpufeatures machinery has been set up.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://patch.msgid.link/all/20251023124629.5385-1-bp@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
x86/microcode/AMD: Add Zen5 model 0x44, stepping 0x1 minrev 2025-11-24T09:30:08+00:00 Borislav Petkov (AMD) bp@alien8.de 2025-11-14T13:01:14+00:00 21bedc6eeb5139288e997538bd465c70c191a791 commit dd14022a7ce96963aa923e35cf4bcc8c32f95840 upstream. Add the minimum Entrysign revision for that model+stepping to the list of minimum revisions. Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches") Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/e94dd76b-4911-482f-8500-5c848a3df026@citrix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dd14022a7ce96963aa923e35cf4bcc8c32f95840 upstream.

Add the minimum Entrysign revision for that model+stepping to the list
of minimum revisions.

Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/e94dd76b-4911-482f-8500-5c848a3df026@citrix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode/AMD: Add more known models to entry sign checking 2025-11-24T09:29:54+00:00 Mario Limonciello (AMD) superm1@kernel.org 2025-11-06T18:28:54+00:00 24bef9ca58306eb94abfefcfd720aa404f19c46e commit d23550efc6800841b4d1639784afaebdea946ae0 upstream. Two Zen5 systems are missing from need_sha_check(). Add them. Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches") Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://patch.msgid.link/20251106182904.4143757-1-superm1@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d23550efc6800841b4d1639784afaebdea946ae0 upstream.

Two Zen5 systems are missing from need_sha_check(). Add them.

Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches")
Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20251106182904.4143757-1-superm1@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode: Fix Entrysign revision check for Zen1/Naples 2025-10-29T13:07:05+00:00 Andrew Cooper andrew.cooper3@citrix.com 2025-10-20T14:41:24+00:00 3a25640814ff8867637037590538b9cd6386e526 commit 876f0d43af78639790bee0e57b39d498ae35adcf upstream. ... to match AMD's statement here: https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7033.html Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches") Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://patch.msgid.link/20251020144124.2930784-1-andrew.cooper3@citrix.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 876f0d43af78639790bee0e57b39d498ae35adcf upstream.

... to match AMD's statement here:

https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7033.html

Fixes: 50cef76d5cb0 ("x86/microcode/AMD: Load only SHA256-checksummed patches")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/20251020144124.2930784-1-andrew.cooper3@citrix.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode/AMD: Handle the case of no BIOS microcode 2025-09-04T13:30:26+00:00 Borislav Petkov (AMD) bp@alien8.de 2025-08-20T09:58:57+00:00 c84ba4cdf4c65eef0f94661ab4cf3895594546a1 commit fcf8239ad6a5de54fa7ce18e464c6b5951b982cb upstream. Machines can be shipped without any microcode in the BIOS. Which means, the microcode patch revision is 0. Handle that gracefully. Fixes: 94838d230a6c ("x86/microcode/AMD: Use the family,model,stepping encoded in the patch ID") Reported-by: Vítek Vávra <vit.vavra.kh@gmail.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fcf8239ad6a5de54fa7ce18e464c6b5951b982cb upstream.

Machines can be shipped without any microcode in the BIOS. Which means,
the microcode patch revision is 0.

Handle that gracefully.

Fixes: 94838d230a6c ("x86/microcode/AMD: Use the family,model,stepping encoded in the patch ID")
Reported-by: Vítek Vávra <vit.vavra.kh@gmail.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/bugs: Add a Transient Scheduler Attacks mitigation 2025-07-10T14:03:21+00:00 Borislav Petkov (AMD) bp@alien8.de 2024-09-11T08:53:08+00:00 90293047df18caf7ed0fe566d89af0720f2dc98a Commit d8010d4ba43e9f790925375a7de100604a5e2dba upstream. Add the required features detection glue to bugs.c et all in order to support the TSA mitigation. Co-developed-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Commit d8010d4ba43e9f790925375a7de100604a5e2dba upstream.

Add the required features detection glue to bugs.c et all in order to
support the TSA mitigation.

Co-developed-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode: Consolidate the loader enablement checking 2025-05-18T06:24:08+00:00 Borislav Petkov (AMD) bp@alien8.de 2025-04-14T09:59:33+00:00 cbd5108119d7c2877737fc76480cfc50ba7088b6 commit 5214a9f6c0f56644acb9d2cbb58facf1856d322b upstream. Consolidate the whole logic which determines whether the microcode loader should be enabled or not into a single function and call it everywhere. Well, almost everywhere - not in mk_early_pgtbl_32() because there the kernel is running without paging enabled and checking dis_ucode_ldr et al would require physical addresses and uglification of the code. But since this is 32-bit, the easier thing to do is to simply map the initrd unconditionally especially since that mapping is getting removed later anyway by zap_early_initrd_mapping() and avoid the uglification. In doing so, address the issue of old 486er machines without CPUID support, not booting current kernels. [ mingo: Fix no previous prototype for ‘microcode_loader_disabled’ [-Wmissing-prototypes] ] Fixes: 4c585af7180c1 ("x86/boot/32: Temporarily map initrd for microcode loading") Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable@kernel.org> Link: https://lore.kernel.org/r/CANpbe9Wm3z8fy9HbgS8cuhoj0TREYEEkBipDuhgkWFvqX0UoVQ@mail.gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5214a9f6c0f56644acb9d2cbb58facf1856d322b upstream.

Consolidate the whole logic which determines whether the microcode loader
should be enabled or not into a single function and call it everywhere.

Well, almost everywhere - not in mk_early_pgtbl_32() because there the kernel
is running without paging enabled and checking dis_ucode_ldr et al would
require physical addresses and uglification of the code.

But since this is 32-bit, the easier thing to do is to simply map the initrd
unconditionally especially since that mapping is getting removed later anyway
by zap_early_initrd_mapping() and avoid the uglification.

In doing so, address the issue of old 486er machines without CPUID
support, not booting current kernels.

  [ mingo: Fix no previous prototype for ‘microcode_loader_disabled’ [-Wmissing-prototypes] ]

Fixes: 4c585af7180c1 ("x86/boot/32: Temporarily map initrd for microcode loading")
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Cc: <stable@kernel.org>
Link: https://lore.kernel.org/r/CANpbe9Wm3z8fy9HbgS8cuhoj0TREYEEkBipDuhgkWFvqX0UoVQ@mail.gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/microcode/AMD: Extend the SHA check to Zen5, block loading of any unreleased standalone Zen5 microcode patches 2025-04-25T08:45:50+00:00 Borislav Petkov (AMD) bp@alien8.de 2025-04-10T11:42:22+00:00 971ba6a64c53fbe3378d11d7295a9fc81c3695ee commit 805b743fc163f1abef7ce1bea8eca8dfab5b685b upstream. All Zen5 machines out there should get BIOS updates which update to the correct microcode patches addressing the microcode signature issue. However, silly people carve out random microcode blobs from BIOS packages and think are doing other people a service this way... Block loading of any unreleased standalone Zen5 microcode patches. Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: <stable@kernel.org> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Cc: Nikolay Borisov <nik.borisov@suse.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Link: https://lore.kernel.org/r/20250410114222.32523-1-bp@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 805b743fc163f1abef7ce1bea8eca8dfab5b685b upstream.

All Zen5 machines out there should get BIOS updates which update to the
correct microcode patches addressing the microcode signature issue.
However, silly people carve out random microcode blobs from BIOS
packages and think are doing other people a service this way...

Block loading of any unreleased standalone Zen5 microcode patches.

Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: <stable@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Cc: Nikolay Borisov <nik.borisov@suse.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Link: https://lore.kernel.org/r/20250410114222.32523-1-bp@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>