From c4d1fcf3a2ea89b6d6221fa8b4588c77aff50995 Mon Sep 17 00:00:00 2001
From: Andi Kleen <ak@suse.de>
Date: Fri, 20 May 2005 14:27:56 -0700
Subject: [PATCH] [PATCH] x86_64: Don't allow accesses below register frame in
ptrace
There was a "off by one quad word" error in there. I don't think it is
exploitable because it will only store into a unused area, but better to plug
it.
Found and fixed by John Blackwood
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/x86_64/kernel/ptrace.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86_64/kernel/ptrace.c b/arch/x86_64/kernel/ptrace.c
index 60dc9b98951d0..525f6a128a279 100644
--- a/arch/x86_64/kernel/ptrace.c
+++ b/arch/x86_64/kernel/ptrace.c
@@ -380,7 +380,7 @@ asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data
break;
switch (addr) {
- case 0 ... sizeof(struct user_regs_struct):
+ case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
tmp = getreg(child, addr);
break;
case offsetof(struct user, u_debugreg[0]):
@@ -425,7 +425,7 @@ asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, long data
break;
switch (addr) {
- case 0 ... sizeof(struct user_regs_struct):
+ case 0 ... sizeof(struct user_regs_struct) - sizeof(long):
ret = putreg(child, addr, data);
break;
/* Disallows to set a breakpoint into the vsyscall */
--
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