FAILED: patch "[PATCH] x86/microcode/intel: Check patch signature before saving" failed to apply to 4.9-stable tree
Subsystems (3)
[email protected]
maintainerThe patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 1a371e67dc77125736cc56d3a0893f06b75855b6 Mon Sep 17 00:00:00 2001
From: Chen Yu <[email protected]>
Date: Fri, 13 Nov 2020 09:59:23 +0800
Subject: [PATCH] x86/microcode/intel: Check patch signature before saving
microcode for early loading
Currently, scan_microcode() leverages microcode_matches() to check if the microcode matches the CPU by comparing the family and model. However, the processor stepping and flags of the microcode signature should also be considered when saving a microcode patch for early update.
Use find_matching_signature() in scan_microcode() and get rid of the now-unused microcode_matches() which is a good cleanup in itself.
Complete the verification of the patch being saved for early loading in save_microcode_patch() directly. This needs to be done there too because save_mc_for_early() will call save_microcode_patch() too.
The second reason why this needs to be done is because the loader still tries to support, at least hypothetically, mixed-steppings systems and thus adds all patches to the cache that belong to the same CPU model albeit with different steppings.
For example:
microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6
microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23
The patch which is being saved for early loading, however, can only be the one which fits the CPU this runs on so do the signature verification before saving.
[ bp: Do signature verification in save_microcode_patch()
and rewrite commit message. ]
arch/x86/kernel/cpu/microcode/intel.c +10 -53
@@ -100,53 +100,6 @@ static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_revreturn find_matching_signature (mc, csig, cpf); } -/* -* Given CPU signature and a microcode patch, this function finds if the -* microcode patch has matching family and model with the CPU. -* -* %true - if there's a match -* %false - otherwise -*/ -static bool microcode_matches (struct microcode_header_intel *mc_header, -unsigned long sig) -{ -unsigned long total_size =get_totalsize (mc_header); -unsigned long data_size =get_datasize (mc_header); -struct extended_sigtable *ext_header; -unsigned int fam_ucode, model_ucode; -struct extended_signature *ext_sig; -unsigned int fam, model; -int ext_sigcount, i; - - fam =x86_family (sig); - model =x86_model (sig); - - fam_ucode =x86_family (mc_header->sig); - model_ucode =x86_model (mc_header->sig); - -if (fam == fam_ucode && model == model_ucode) -return true; - -/* Look for ext. headers: */ -if (total_size <= data_size +MC_HEADER_SIZE ) -return false; - - ext_header = (void *) mc_header + data_size +MC_HEADER_SIZE ; - ext_sig = (void *)ext_header +EXT_HEADER_SIZE ; - ext_sigcount = ext_header->count; - -for (i =0 ; i < ext_sigcount; i++) { - fam_ucode =x86_family (ext_sig->sig); - model_ucode =x86_model (ext_sig->sig); - -if (fam == fam_ucode && model == model_ucode) -return true; - - ext_sig++; - } -return false; -} -static struct ucode_patch *memdup_patch (void *data,unsigned int size) {struct ucode_patch *p;
@@ -164,7 +117,7 @@ static struct ucode_patch *memdup_patch(void *data, unsigned int size)return p; } -static void save_microcode_patch (void *data,unsigned int size) +static void save_microcode_patch (struct ucode_cpu_info *uci,void *data,unsigned int size) {struct microcode_header_intel *mc_hdr, *mc_saved_hdr;struct ucode_patch *iter, *tmp, *p =NULL ;
@@ -210,6 +163,9 @@ static void save_microcode_patch(void *data, unsigned int size)if (!p)return ; +if (!find_matching_signature (p->data, uci->cpu_sig.sig, uci->cpu_sig.pf)) +return ; +/* * Save for early loading. On 32-bit, that needs to be a physical * address as the APs are running from physical addresses, before
@@ -344,13 +300,14 @@ scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save) size -= mc_size; -if (!microcode_matches (mc_header, uci->cpu_sig.sig)) { +if (!find_matching_signature (data, uci->cpu_sig.sig, + uci->cpu_sig.pf)) { data += mc_size;continue ; }if (save) { -save_microcode_patch (data, mc_size); +save_microcode_patch (uci, data, mc_size); goto next; }
@@ -483,14 +440,14 @@ static void show_saved_mc(void)* Save this microcode patch. It will be loaded early when a CPU is * hot-added or resumes. */ -static void save_mc_for_early (u8 *mc,unsigned int size) +static void save_mc_for_early (struct ucode_cpu_info *uci,u8 *mc,unsigned int size) {/* Synchronization during CPU hotplug. */ static DEFINE_MUTEX (x86_cpu_microcode_mutex);mutex_lock (&x86_cpu_microcode_mutex); -save_microcode_patch (mc, size); +save_microcode_patch (uci, mc, size);show_saved_mc ();mutex_unlock (&x86_cpu_microcode_mutex);
@@ -935,7 +892,7 @@ static enum ucode_state generic_load_microcode(int cpu, struct iov_iter *iter)* permanent memory. So it will be loaded early when a CPU is hot added * or resumes. */ -save_mc_for_early (new_mc, new_mc_size); +save_mc_for_early (uci, new_mc, new_mc_size);pr_debug ("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n" , cpu, new_rev, uci->cpu_sig.rev);
Quoted 5 lines · On Mon, Nov 23, 2020 at 10:46:03AM +0100, [email protected] wrote:
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
---
From: Chen Yu <[email protected]>
Date: Fri, 13 Nov 2020 09:59:23 +0800
Subject: [PATCH] x86/microcode/intel: Check patch signature before saving
microcode for early loading
Commit 1a371e67dc77125736cc56d3a0893f06b75855b6 upstream.
Currently, scan_microcode() leverages microcode_matches() to check if the microcode matches the CPU by comparing the family and model. However, the processor stepping and flags of the microcode signature should also be considered when saving a microcode patch for early update.
Use find_matching_signature() in scan_microcode() and get rid of the now-unused microcode_matches() which is a good cleanup in itself.
Complete the verification of the patch being saved for early loading in save_microcode_patch() directly. This needs to be done there too because save_mc_for_early() will call save_microcode_patch() too.
The second reason why this needs to be done is because the loader still tries to support, at least hypothetically, mixed-steppings systems and thus adds all patches to the cache that belong to the same CPU model albeit with different steppings.
For example:
microcode: CPU: sig=0x906ec, pf=0x2, rev=0xd6
microcode: mc_saved[0]: sig=0x906e9, pf=0x2a, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[1]: sig=0x906ea, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[2]: sig=0x906eb, pf=0x2, rev=0xd6, total size=0x19400, date = 2020-04-23
microcode: mc_saved[3]: sig=0x906ec, pf=0x22, rev=0xd6, total size=0x19000, date = 2020-04-27
microcode: mc_saved[4]: sig=0x906ed, pf=0x22, rev=0xd6, total size=0x19400, date = 2020-04-23
The patch which is being saved for early loading, however, can only be the one which fits the CPU this runs on so do the signature verification before saving.
[ bp: Do signature verification in save_microcode_patch()
and rewrite commit message. ]
--- arch/x86/kernel/cpu/microcode/intel.c | 48 ++------------------------- 1 file changed, 2 insertions(+), 46 deletions(-)
arch/x86/kernel/cpu/microcode/intel.c +2 -46
@@ -147,51 +147,6 @@ load_microcode(struct mc_saved_data *mcs, unsigned long *mc_ptrs, } } -/* -* Given CPU signature and a microcode patch, this function finds if the -* microcode patch has matching family and model with the CPU. -*/ -static enum ucode_state -matching_model_microcode (struct microcode_header_intel *mc_header, -unsigned long sig) -{ -unsigned int fam, model; -unsigned int fam_ucode, model_ucode; -struct extended_sigtable *ext_header; -unsigned long total_size =get_totalsize (mc_header); -unsigned long data_size =get_datasize (mc_header); -int ext_sigcount, i; -struct extended_signature *ext_sig; - - fam =x86_family (sig); - model =x86_model (sig); - - fam_ucode =x86_family (mc_header->sig); - model_ucode =x86_model (mc_header->sig); - -if (fam == fam_ucode && model == model_ucode) -return UCODE_OK ; - -/* Look for ext. headers: */ -if (total_size <= data_size +MC_HEADER_SIZE ) -return UCODE_NFOUND ; - - ext_header = (void *) mc_header + data_size +MC_HEADER_SIZE ; - ext_sig = (void *)ext_header +EXT_HEADER_SIZE ; - ext_sigcount = ext_header->count; - -for (i =0 ; i < ext_sigcount; i++) { - fam_ucode =x86_family (ext_sig->sig); - model_ucode =x86_model (ext_sig->sig); - -if (fam == fam_ucode && model == model_ucode) -return UCODE_OK ; - - ext_sig++; - } -return UCODE_NFOUND ; -} - static int save_microcode(struct mc_saved_data *mcs, struct microcode_intel **mc_saved_src,
@@ -332,7 +287,8 @@ get_matching_model_microcode(unsigned long start, void *data, size_t size,* the platform, we need to find and save microcode patches * with the same family and model as the BSP. */ -if (matching_model_microcode (mc_header, uci->cpu_sig.sig) !=UCODE_OK ) { +if (!find_matching_signature (mc_header, uci->cpu_sig.sig, + uci->cpu_sig.pf)) { ucode_ptr += mc_size;continue ; }
Signature · 7 lines
2.21.0
--
Regards/Gruss,
Boris.
SUSE Software Solutions Germany GmbH, GF: Felix Imendörffer, HRB 36809, AG NürnbergGreg KH
maintainerQuoted 7 lines · Borislav Petkov
Quoted 5 lines · On Mon, Nov 23, 2020 at 10:46:03AM +0100, [email protected] wrote:
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
Quoted 7 lines
---
From: Chen Yu <[email protected]>
Date: Fri, 13 Nov 2020 09:59:23 +0800
Subject: [PATCH] x86/microcode/intel: Check patch signature before saving
microcode for early loadingCommit
1a371e67dc77125736cc56d3a0893f06b75855b6upstream.
This, and the 4.4.y backport, now queued up, thanks.
greg k-h