Merge branch 'master' of ssh://master.kernel.org/pub/scm/linux/kernel/git/kaber/nf-2.6

1 files changed, 10 insertions, 1 deletions

diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c
index a7934ac75e5..5f9e689dc8f 100644
--- a/kernel/futex_compat.c
+++ b/kernel/futex_compat.c
@@ -153,10 +153,19 @@ compat_sys_get_robust_list(int pid, compat_uptr_t __user *head_ptr,
 			goto err_unlock;
 		ret = -EPERM;
 		pcred = __task_cred(p);
+		/* If victim is in different user_ns, then uids are not
+		   comparable, so we must have CAP_SYS_PTRACE */
+		if (cred->user->user_ns != pcred->user->user_ns) {
+			if (!ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
+				goto err_unlock;
+			goto ok;
+		}
+		/* If victim is in same user_ns, then uids are comparable */
 		if (cred->euid != pcred->euid &&
 		    cred->euid != pcred->uid &&
-		    !capable(CAP_SYS_PTRACE))
+		    !ns_capable(pcred->user->user_ns, CAP_SYS_PTRACE))
 			goto err_unlock;
+ok:
 		head = p->compat_robust_list;
 		rcu_read_unlock();
 	}