[PATCH] make cap_ptrace enforce PTRACE_TRACME checks

PTRACE_TRACEME doesn't have proper capabilities validation when parent is
less privileged than child.  Issue pointed out by Ram Gupta
<ram.gupta5@gmail.com>.

Note: I haven't identified a strong security issue, and it's a small ABI
change that could break apps that rely on existing behaviour (which allows
parent that is less privileged than child to ptrace when child does
PTRACE_TRACEME).

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Ram Gupta <ram.gupta5@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Chris Wright 2006-03-25 03:07:41 -08:00 committed by Linus Torvalds
parent 12b5989be1
commit d4eb82c783

View file

@ -60,8 +60,8 @@ int cap_settime(struct timespec *ts, struct timezone *tz)
int cap_ptrace (struct task_struct *parent, struct task_struct *child)
{
/* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */
if (!cap_issubset (child->cap_permitted, current->cap_permitted) &&
!capable(CAP_SYS_PTRACE))
if (!cap_issubset(child->cap_permitted, parent->cap_permitted) &&
!__capable(parent, CAP_SYS_PTRACE))
return -EPERM;
return 0;
}