From: Andi Kleen <ak@suse.de>
Date: Tue, 17 May 2005 04:53:29 +0000 (-0700)
Subject: [PATCH] x86_64: check if ptrace RIP is canonical
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d1099e8a18960693c04507bdd7b9403db70bfd97;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

[PATCH] x86_64: check if ptrace RIP is canonical

This works around an AMD Erratum.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index e26e86bb56fe..892212161aa8 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -277,6 +277,11 @@ static int putreg(struct task_struct *child,
 				return -EIO;
 			value &= 0xffff;
 			break;
+		case offsetof(struct user_regs_struct, rip):
+			/* Check if the new RIP address is canonical */
+			if (value >= TASK_SIZE)
+				return -EIO;
+			break;
 	}
 	put_stack_long(child, regno - sizeof(struct pt_regs), value);
 	return 0;