linux-kernel - [RFC PATCH v5 4/7] mseal, system mappings: enable arm64

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20250212032155.1276806-5-jeffxu@google.com>
Date: Wed, 12 Feb 2025 03:21:52 +0000
From: jeffxu@...omium.org
To: akpm@...ux-foundation.org,
	keescook@...omium.org,
	jannh@...gle.com,
	torvalds@...ux-foundation.org,
	vbabka@...e.cz,
	lorenzo.stoakes@...cle.com,
	Liam.Howlett@...cle.com,
	adhemerval.zanella@...aro.org,
	oleg@...hat.com,
	avagin@...il.com,
	benjamin@...solutions.net
Cc: linux-kernel@...r.kernel.org,
	linux-hardening@...r.kernel.org,
	linux-mm@...ck.org,
	jorgelo@...omium.org,
	sroettger@...gle.com,
	hch@....de,
	ojeda@...nel.org,
	thomas.weissschuh@...utronix.de,
	adobriyan@...il.com,
	johannes@...solutions.net,
	pedro.falcato@...il.com,
	hca@...ux.ibm.com,
	willy@...radead.org,
	anna-maria@...utronix.de,
	mark.rutland@....com,
	linus.walleij@...aro.org,
	Jason@...c4.com,
	deller@....de,
	rdunlap@...radead.org,
	davem@...emloft.net,
	peterx@...hat.com,
	f.fainelli@...il.com,
	gerg@...nel.org,
	dave.hansen@...ux.intel.com,
	mingo@...nel.org,
	ardb@...nel.org,
	mhocko@...e.com,
	42.hyeyoo@...il.com,
	peterz@...radead.org,
	ardb@...gle.com,
	enh@...gle.com,
	rientjes@...gle.com,
	groeck@...omium.org,
	mpe@...erman.id.au,
	aleksandr.mikhalitsyn@...onical.com,
	mike.rapoport@...il.com,
	Jeff Xu <jeffxu@...omium.org>
Subject: [RFC PATCH v5 4/7] mseal, system mappings: enable arm64

From: Jeff Xu <jeffxu@...omium.org>

Provide support for CONFIG_MSEAL_SYSTEM_MAPPINGS on arm64, covering
the vdso, vvar, and compat-mode vectors and sigpage mappings.

Production release testing passes on Android and Chrome OS.

Signed-off-by: Jeff Xu <jeffxu@...omium.org>
---
 arch/arm64/Kconfig       |  1 +
 arch/arm64/kernel/vdso.c | 23 ++++++++++++++++-------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fcdd0ed3eca8..39202aa9a5af 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -38,6 +38,7 @@ config ARM64
 	select ARCH_HAS_KEEPINITRD
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_MEM_ENCRYPT
+	select ARCH_HAS_MSEAL_SYSTEM_MAPPINGS
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index e8ed8e5b713b..cfe2f5b344c4 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -15,6 +15,7 @@
 #include <linux/gfp.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/userprocess.h>
 #include <linux/sched.h>
 #include <linux/signal.h>
 #include <linux/slab.h>
@@ -183,6 +184,7 @@ static int __setup_additional_pages(enum vdso_abi abi,
 {
 	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
 	unsigned long gp_flags = 0;
+	unsigned long vm_flags;
 	void *ret;
 
 	BUILD_BUG_ON(VVAR_NR_PAGES != __VVAR_PAGES);
@@ -197,8 +199,10 @@ static int __setup_additional_pages(enum vdso_abi abi,
 		goto up_fail;
 	}
 
+	vm_flags = VM_READ|VM_MAYREAD|VM_PFNMAP;
+	vm_flags |= mseal_system_mappings();
 	ret = _install_special_mapping(mm, vdso_base, VVAR_NR_PAGES * PAGE_SIZE,
-				       VM_READ|VM_MAYREAD|VM_PFNMAP,
+				       vm_flags,
 				       &vvar_map);
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -208,9 +212,10 @@ static int __setup_additional_pages(enum vdso_abi abi,
 
 	vdso_base += VVAR_NR_PAGES * PAGE_SIZE;
 	mm->context.vdso = (void *)vdso_base;
+	vm_flags = VM_READ|VM_EXEC|gp_flags|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
+	vm_flags |= mseal_system_mappings();
 	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
-				       VM_READ|VM_EXEC|gp_flags|
-				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+				       vm_flags,
 				       vdso_info[abi].cm);
 	if (IS_ERR(ret))
 		goto up_fail;
@@ -326,6 +331,7 @@ arch_initcall(aarch32_alloc_vdso_pages);
 static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
 {
 	void *ret;
+	unsigned long vm_flags;
 
 	if (!IS_ENABLED(CONFIG_KUSER_HELPERS))
 		return 0;
@@ -334,9 +340,10 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
 	 * Avoid VM_MAYWRITE for compatibility with arch/arm/, where it's
 	 * not safe to CoW the page containing the CPU exception vectors.
 	 */
+	vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC;
+	vm_flags |= mseal_system_mappings();
 	ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE,
-				       VM_READ | VM_EXEC |
-				       VM_MAYREAD | VM_MAYEXEC,
+				       vm_flags,
 				       &aarch32_vdso_maps[AA32_MAP_VECTORS]);
 
 	return PTR_ERR_OR_ZERO(ret);
@@ -345,6 +352,7 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
 static int aarch32_sigreturn_setup(struct mm_struct *mm)
 {
 	unsigned long addr;
+	unsigned long vm_flags;
 	void *ret;
 
 	addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
@@ -357,9 +365,10 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
 	 * VM_MAYWRITE is required to allow gdb to Copy-on-Write and
 	 * set breakpoints.
 	 */
+	vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
+	vm_flags |= mseal_system_mappings();
 	ret = _install_special_mapping(mm, addr, PAGE_SIZE,
-				       VM_READ | VM_EXEC | VM_MAYREAD |
-				       VM_MAYWRITE | VM_MAYEXEC,
+				       vm_flags,
 				       &aarch32_vdso_maps[AA32_MAP_SIGPAGE]);
 	if (IS_ERR(ret))
 		goto out;
-- 
2.48.1.502.g6dc24dfdaf-goog