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From: Coiby Xu <coxu@redhat.com>
To: kexec@lists.infradead.org
Cc: "maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" <x86@kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>, Baoquan He <bhe@redhat.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	dm-devel@redhat.com, Pingfan Liu <kernelfans@gmail.com>,
	linux-kernel@vger.kernel.org, Kairui Song <ryncsn@gmail.com>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Jan Pazdziora <jpazdziora@redhat.com>,
	Thomas Staudt <tstaudt@de.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Dave Young <dyoung@redhat.com>, Milan Broz <gmazyland@gmail.com>
Subject: [dm-devel] [RFC v2 4/5] x86/crash: make the page that stores the LUKS volume key inaccessible
Date: Fri,  4 Nov 2022 19:29:59 +0800	[thread overview]
Message-ID: <20221104113000.487098-5-coxu@redhat.com> (raw)
In-Reply-To: <20221104113000.487098-1-coxu@redhat.com>

This adds an addition layer of protection for the saved copy of LUKS
volume key. Trying to access the saved copy will cause page fault.

Suggested-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/x86/kernel/machine_kexec_64.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 0611fd83858e..f3d51c38a1c9 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -557,9 +557,25 @@ static void kexec_mark_crashkres(bool protect)
 	kexec_mark_range(control, crashk_res.end, protect);
 }
 
+static void kexec_mark_luks_volume_key_inaccessible(void)
+{
+	unsigned long start, end;
+	struct page *page;
+	unsigned int nr_pages;
+
+	if (kexec_crash_image->luks_volume_key_addr) {
+		start = kexec_crash_image->luks_volume_key_addr;
+		end = start + kexec_crash_image->luks_volume_key_sz - 1;
+		page = pfn_to_page(start >> PAGE_SHIFT);
+		nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
+		set_memory_np((unsigned long)page_address(page), nr_pages);
+	}
+}
+
 void arch_kexec_protect_crashkres(void)
 {
 	kexec_mark_crashkres(true);
+	kexec_mark_luks_volume_key_inaccessible();
 }
 
 void arch_kexec_unprotect_crashkres(void)
-- 
2.37.3

--
dm-devel mailing list
dm-devel@redhat.com
https://listman.redhat.com/mailman/listinfo/dm-devel


WARNING: multiple messages have this Message-ID (diff)
From: Coiby Xu <coxu@redhat.com>
To: kexec@lists.infradead.org
Cc: Milan Broz <gmazyland@gmail.com>,
	Thomas Staudt <tstaudt@de.ibm.com>,
	Kairui Song <ryncsn@gmail.com>,
	dm-devel@redhat.com, Jan Pazdziora <jpazdziora@redhat.com>,
	Pingfan Liu <kernelfans@gmail.com>, Baoquan He <bhe@redhat.com>,
	Dave Young <dyoung@redhat.com>,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [RFC v2 4/5] x86/crash: make the page that stores the LUKS volume key inaccessible
Date: Fri,  4 Nov 2022 19:29:59 +0800	[thread overview]
Message-ID: <20221104113000.487098-5-coxu@redhat.com> (raw)
In-Reply-To: <20221104113000.487098-1-coxu@redhat.com>

This adds an addition layer of protection for the saved copy of LUKS
volume key. Trying to access the saved copy will cause page fault.

Suggested-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/x86/kernel/machine_kexec_64.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 0611fd83858e..f3d51c38a1c9 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -557,9 +557,25 @@ static void kexec_mark_crashkres(bool protect)
 	kexec_mark_range(control, crashk_res.end, protect);
 }
 
+static void kexec_mark_luks_volume_key_inaccessible(void)
+{
+	unsigned long start, end;
+	struct page *page;
+	unsigned int nr_pages;
+
+	if (kexec_crash_image->luks_volume_key_addr) {
+		start = kexec_crash_image->luks_volume_key_addr;
+		end = start + kexec_crash_image->luks_volume_key_sz - 1;
+		page = pfn_to_page(start >> PAGE_SHIFT);
+		nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
+		set_memory_np((unsigned long)page_address(page), nr_pages);
+	}
+}
+
 void arch_kexec_protect_crashkres(void)
 {
 	kexec_mark_crashkres(true);
+	kexec_mark_luks_volume_key_inaccessible();
 }
 
 void arch_kexec_unprotect_crashkres(void)
-- 
2.37.3


_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

WARNING: multiple messages have this Message-ID (diff)
From: Coiby Xu <coxu@redhat.com>
To: kexec@lists.infradead.org
Cc: Milan Broz <gmazyland@gmail.com>,
	Thomas Staudt <tstaudt@de.ibm.com>,
	Kairui Song <ryncsn@gmail.com>,
	dm-devel@redhat.com, Jan Pazdziora <jpazdziora@redhat.com>,
	Pingfan Liu <kernelfans@gmail.com>, Baoquan He <bhe@redhat.com>,
	Dave Young <dyoung@redhat.com>,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	"H. Peter Anvin" <hpa@zytor.com>
Subject: [RFC v2 4/5] x86/crash: make the page that stores the LUKS volume key inaccessible
Date: Fri,  4 Nov 2022 19:29:59 +0800	[thread overview]
Message-ID: <20221104113000.487098-5-coxu@redhat.com> (raw)
In-Reply-To: <20221104113000.487098-1-coxu@redhat.com>

This adds an addition layer of protection for the saved copy of LUKS
volume key. Trying to access the saved copy will cause page fault.

Suggested-by: Pingfan Liu <kernelfans@gmail.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
---
 arch/x86/kernel/machine_kexec_64.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
index 0611fd83858e..f3d51c38a1c9 100644
--- a/arch/x86/kernel/machine_kexec_64.c
+++ b/arch/x86/kernel/machine_kexec_64.c
@@ -557,9 +557,25 @@ static void kexec_mark_crashkres(bool protect)
 	kexec_mark_range(control, crashk_res.end, protect);
 }
 
+static void kexec_mark_luks_volume_key_inaccessible(void)
+{
+	unsigned long start, end;
+	struct page *page;
+	unsigned int nr_pages;
+
+	if (kexec_crash_image->luks_volume_key_addr) {
+		start = kexec_crash_image->luks_volume_key_addr;
+		end = start + kexec_crash_image->luks_volume_key_sz - 1;
+		page = pfn_to_page(start >> PAGE_SHIFT);
+		nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
+		set_memory_np((unsigned long)page_address(page), nr_pages);
+	}
+}
+
 void arch_kexec_protect_crashkres(void)
 {
 	kexec_mark_crashkres(true);
+	kexec_mark_luks_volume_key_inaccessible();
 }
 
 void arch_kexec_unprotect_crashkres(void)
-- 
2.37.3


  parent reply	other threads:[~2022-11-07  8:40 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-04 11:29 [dm-devel] [RFC v2 0/5] Support kdump with LUKS encryption by reusing LUKS volume key Coiby Xu
2022-11-04 11:29 ` Coiby Xu
2022-11-04 11:29 ` Coiby Xu
2022-11-04 11:29 ` [dm-devel] [RFC v2 1/5] kexec_file: allow to place kexec_buf randomly Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 11:29 ` [dm-devel] [RFC v2 2/5] crash_dump: save the LUKS volume key temporarily Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 11:29 ` [dm-devel] [RFC v2 3/5] x86/crash: pass the LUKS volume key to kdump kernel Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 11:29 ` Coiby Xu [this message]
2022-11-04 11:29   ` [RFC v2 4/5] x86/crash: make the page that stores the LUKS volume key inaccessible Coiby Xu
2022-11-04 11:29   ` Coiby Xu
2022-11-04 14:38   ` [dm-devel] " Dave Hansen
2022-11-04 14:38     ` Dave Hansen
2022-11-04 14:38     ` Dave Hansen
2022-11-07 11:20     ` [dm-devel] " Coiby Xu
2022-11-07 11:20       ` Coiby Xu
2022-11-07 11:20       ` Coiby Xu
2022-11-04 11:30 ` [dm-devel] [RFC v2 5/5] crash_dump: retrieve LUKS volume key in kdump kernel Coiby Xu
2022-11-04 11:30   ` Coiby Xu
2022-11-04 11:30   ` Coiby Xu
2023-02-01  8:18 ` [dm-devel] [RFC v2 0/5] Support kdump with LUKS encryption by reusing LUKS volume key Baoquan He
2023-02-01  8:18   ` Baoquan He
2023-02-01  8:18   ` Baoquan He

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