diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0002-x86-entry-64-compat-Clear-registers-for-compat-sysca.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0002-x86-entry-64-compat-Clear-registers-for-compat-sysca.patch | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0002-x86-entry-64-compat-Clear-registers-for-compat-sysca.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0002-x86-entry-64-compat-Clear-registers-for-compat-sysca.patch new file mode 100644 index 00000000..1006a947 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0002-x86-entry-64-compat-Clear-registers-for-compat-sysca.patch @@ -0,0 +1,117 @@ +From 5b4a083e3f13f1bbea53075da6dc33b1e9dc3b62 Mon Sep 17 00:00:00 2001 +From: Dan Williams <dan.j.williams@intel.com> +Date: Mon, 5 Feb 2018 17:18:17 -0800 +Subject: [PATCH 02/12] x86/entry/64/compat: Clear registers for compat + syscalls, to reduce speculation attack surface + +commit 6b8cf5cc9965673951f1ab3f0e3cf23d06e3e2ee upstream. + +At entry userspace may have populated registers with values that could +otherwise be useful in a speculative execution attack. Clear them to +minimize the kernel's attack surface. + +Originally-From: Andi Kleen <ak@linux.intel.com> +Signed-off-by: Dan Williams <dan.j.williams@intel.com> +Cc: <stable@vger.kernel.org> +Cc: Andy Lutomirski <luto@kernel.org> +Cc: Borislav Petkov <bp@alien8.de> +Cc: Brian Gerst <brgerst@gmail.com> +Cc: Denys Vlasenko <dvlasenk@redhat.com> +Cc: H. Peter Anvin <hpa@zytor.com> +Cc: Josh Poimboeuf <jpoimboe@redhat.com> +Cc: Linus Torvalds <torvalds@linux-foundation.org> +Cc: Peter Zijlstra <peterz@infradead.org> +Cc: Thomas Gleixner <tglx@linutronix.de> +Link: http://lkml.kernel.org/r/151787989697.7847.4083702787288600552.stgit@dwillia2-desk3.amr.corp.intel.com +[ Made small improvements to the changelog. ] +Signed-off-by: Ingo Molnar <mingo@kernel.org> +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/entry/entry_64_compat.S | 30 ++++++++++++++++++++++++++++++ + 1 file changed, 30 insertions(+) + +diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S +index d76a976..92c5573 100644 +--- a/arch/x86/entry/entry_64_compat.S ++++ b/arch/x86/entry/entry_64_compat.S +@@ -83,15 +83,25 @@ ENTRY(entry_SYSENTER_compat) + pushq %rcx /* pt_regs->cx */ + pushq $-ENOSYS /* pt_regs->ax */ + pushq $0 /* pt_regs->r8 = 0 */ ++ xorq %r8, %r8 /* nospec r8 */ + pushq $0 /* pt_regs->r9 = 0 */ ++ xorq %r9, %r9 /* nospec r9 */ + pushq $0 /* pt_regs->r10 = 0 */ ++ xorq %r10, %r10 /* nospec r10 */ + pushq $0 /* pt_regs->r11 = 0 */ ++ xorq %r11, %r11 /* nospec r11 */ + pushq %rbx /* pt_regs->rbx */ ++ xorl %ebx, %ebx /* nospec rbx */ + pushq %rbp /* pt_regs->rbp (will be overwritten) */ ++ xorl %ebp, %ebp /* nospec rbp */ + pushq $0 /* pt_regs->r12 = 0 */ ++ xorq %r12, %r12 /* nospec r12 */ + pushq $0 /* pt_regs->r13 = 0 */ ++ xorq %r13, %r13 /* nospec r13 */ + pushq $0 /* pt_regs->r14 = 0 */ ++ xorq %r14, %r14 /* nospec r14 */ + pushq $0 /* pt_regs->r15 = 0 */ ++ xorq %r15, %r15 /* nospec r15 */ + cld + + /* +@@ -209,15 +219,25 @@ ENTRY(entry_SYSCALL_compat) + pushq %rbp /* pt_regs->cx (stashed in bp) */ + pushq $-ENOSYS /* pt_regs->ax */ + pushq $0 /* pt_regs->r8 = 0 */ ++ xorq %r8, %r8 /* nospec r8 */ + pushq $0 /* pt_regs->r9 = 0 */ ++ xorq %r9, %r9 /* nospec r9 */ + pushq $0 /* pt_regs->r10 = 0 */ ++ xorq %r10, %r10 /* nospec r10 */ + pushq $0 /* pt_regs->r11 = 0 */ ++ xorq %r11, %r11 /* nospec r11 */ + pushq %rbx /* pt_regs->rbx */ ++ xorl %ebx, %ebx /* nospec rbx */ + pushq %rbp /* pt_regs->rbp (will be overwritten) */ ++ xorl %ebp, %ebp /* nospec rbp */ + pushq $0 /* pt_regs->r12 = 0 */ ++ xorq %r12, %r12 /* nospec r12 */ + pushq $0 /* pt_regs->r13 = 0 */ ++ xorq %r13, %r13 /* nospec r13 */ + pushq $0 /* pt_regs->r14 = 0 */ ++ xorq %r14, %r14 /* nospec r14 */ + pushq $0 /* pt_regs->r15 = 0 */ ++ xorq %r15, %r15 /* nospec r15 */ + + /* + * User mode is traced as though IRQs are on, and SYSENTER +@@ -320,15 +340,25 @@ ENTRY(entry_INT80_compat) + pushq %rcx /* pt_regs->cx */ + pushq $-ENOSYS /* pt_regs->ax */ + pushq $0 /* pt_regs->r8 = 0 */ ++ xorq %r8, %r8 /* nospec r8 */ + pushq $0 /* pt_regs->r9 = 0 */ ++ xorq %r9, %r9 /* nospec r9 */ + pushq $0 /* pt_regs->r10 = 0 */ ++ xorq %r10, %r10 /* nospec r10 */ + pushq $0 /* pt_regs->r11 = 0 */ ++ xorq %r11, %r11 /* nospec r11 */ + pushq %rbx /* pt_regs->rbx */ ++ xorl %ebx, %ebx /* nospec rbx */ + pushq %rbp /* pt_regs->rbp */ ++ xorl %ebp, %ebp /* nospec rbp */ + pushq %r12 /* pt_regs->r12 */ ++ xorq %r12, %r12 /* nospec r12 */ + pushq %r13 /* pt_regs->r13 */ ++ xorq %r13, %r13 /* nospec r13 */ + pushq %r14 /* pt_regs->r14 */ ++ xorq %r14, %r14 /* nospec r14 */ + pushq %r15 /* pt_regs->r15 */ ++ xorq %r15, %r15 /* nospec r15 */ + cld + + /* +-- +2.7.4 + |