Il 25/07/2014 15:47, David Drysdale ha scritto:
quoted hunk ↗ jump to hunk
@@ -1996,6 +2013,17 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
if (arg2 || arg3 || arg4 || arg5)
return -EINVAL;
return current->no_new_privs ? 1 : 0;
+ case PR_SET_OPENAT_BENEATH:
+ if (arg2 != 1 || arg4 || arg5)
+ return -EINVAL;
+ if ((arg3 & ~(PR_SET_OPENAT_BENEATH_TSYNC)) != 0)
+ return -EINVAL;
+ error = prctl_set_openat_beneath(me, arg3);
+ break;
+ case PR_GET_OPENAT_BENEATH:
+ if (arg2 || arg3 || arg4 || arg5)
+ return -EINVAL;
+ return me->openat_beneath;
case PR_GET_THP_DISABLE:
if (arg2 || arg3 || arg4 || arg5)
return -EINVAL;
Why are you always forbidding a change of prctl from 1 to 0? It should
be safe if current->no_new_privs is clear.
Do new threads inherit from the parent?
Also, I wonder if you need something like this check:
/*
* Installing a seccomp filter requires that the task has
* CAP_SYS_ADMIN in its namespace or be running with no_new_privs.
* This avoids scenarios where unprivileged tasks can affect the
* behavior of privileged children.
*/
if (!current->no_new_privs &&
security_capable_noaudit(current_cred(), current_user_ns(),
CAP_SYS_ADMIN) != 0)
return -EACCES;
Paolo