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Commit | Line | Data |
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321d628a FG |
1 | From 4eeffdaf7e8e034633bab44f61c5f92002179d28 Mon Sep 17 00:00:00 2001 |
2 | From: Thomas Gleixner <tglx@linutronix.de> | |
3 | Date: Mon, 4 Dec 2017 15:07:43 +0100 | |
4 | Subject: [PATCH 197/231] x86/mm/pti: Force entry through trampoline when PTI | |
5 | active | |
6 | MIME-Version: 1.0 | |
7 | Content-Type: text/plain; charset=UTF-8 | |
8 | Content-Transfer-Encoding: 8bit | |
9 | ||
10 | CVE-2017-5754 | |
11 | ||
12 | Force the entry through the trampoline only when PTI is active. Otherwise | |
13 | go through the normal entry code. | |
14 | ||
15 | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> | |
16 | Reviewed-by: Borislav Petkov <bp@suse.de> | |
17 | Cc: Andy Lutomirski <luto@kernel.org> | |
18 | Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> | |
19 | Cc: Borislav Petkov <bp@alien8.de> | |
20 | Cc: Brian Gerst <brgerst@gmail.com> | |
21 | Cc: Dave Hansen <dave.hansen@linux.intel.com> | |
22 | Cc: David Laight <David.Laight@aculab.com> | |
23 | Cc: Denys Vlasenko <dvlasenk@redhat.com> | |
24 | Cc: Eduardo Valentin <eduval@amazon.com> | |
25 | Cc: Greg KH <gregkh@linuxfoundation.org> | |
26 | Cc: H. Peter Anvin <hpa@zytor.com> | |
27 | Cc: Josh Poimboeuf <jpoimboe@redhat.com> | |
28 | Cc: Juergen Gross <jgross@suse.com> | |
29 | Cc: Linus Torvalds <torvalds@linux-foundation.org> | |
30 | Cc: Peter Zijlstra <peterz@infradead.org> | |
31 | Cc: Will Deacon <will.deacon@arm.com> | |
32 | Cc: aliguori@amazon.com | |
33 | Cc: daniel.gruss@iaik.tugraz.at | |
34 | Cc: hughd@google.com | |
35 | Cc: keescook@google.com | |
36 | Signed-off-by: Ingo Molnar <mingo@kernel.org> | |
37 | (cherry picked from commit 8d4b067895791ab9fdb1aadfc505f64d71239dd2) | |
38 | Signed-off-by: Andy Whitcroft <apw@canonical.com> | |
39 | Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> | |
40 | (cherry picked from commit 9ae1ea4821648be179a96fe65b3ed4bd111a5c98) | |
41 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
42 | --- | |
43 | arch/x86/kernel/cpu/common.c | 5 ++++- | |
44 | 1 file changed, 4 insertions(+), 1 deletion(-) | |
45 | ||
46 | diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c | |
47 | index 623ba3635793..99f37d1636ff 100644 | |
48 | --- a/arch/x86/kernel/cpu/common.c | |
49 | +++ b/arch/x86/kernel/cpu/common.c | |
50 | @@ -1340,7 +1340,10 @@ void syscall_init(void) | |
51 | (entry_SYSCALL_64_trampoline - _entry_trampoline); | |
52 | ||
53 | wrmsr(MSR_STAR, 0, (__USER32_CS << 16) | __KERNEL_CS); | |
54 | - wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline); | |
55 | + if (static_cpu_has(X86_FEATURE_PTI)) | |
56 | + wrmsrl(MSR_LSTAR, SYSCALL64_entry_trampoline); | |
57 | + else | |
58 | + wrmsrl(MSR_LSTAR, (unsigned long)entry_SYSCALL_64); | |
59 | ||
60 | #ifdef CONFIG_IA32_EMULATION | |
61 | wrmsrl(MSR_CSTAR, (unsigned long)entry_SYSCALL_compat); | |
62 | -- | |
63 | 2.14.2 | |
64 |