[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>
This commit is contained in:
Andi Kleen 2005-05-20 14:27:56 -07:00 committed by Linus Torvalds
parent b41e29398a
commit c4d1fcf3a2

View file

@ -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 */