path: root/kernel/futex.c
diff options
authorSerge E. Hallyn <serge@hallyn.com>2011-03-23 16:43:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-23 19:47:08 -0700
commitb0e77598f87107001a00b8a4ece9c95e4254ccc4 (patch)
tree2738276570e4faa7c92a64521c192f04dca93801 /kernel/futex.c
parentb515498f5bb5f38fc0e390b4ff7d00b6077de127 (diff)
userns: user namespaces: convert several capable() calls
CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(), because the resource comes from current's own ipc namespace. setuid/setgid are to uids in own namespace, so again checks can be against current_user_ns(). Changelog: Jan 11: Use task_ns_capable() in place of sched_capable(). Jan 11: Use nsown_capable() as suggested by Bastian Blank. Jan 11: Clarify (hopefully) some logic in futex and sched.c Feb 15: use ns_capable for ipc, not nsown_capable Feb 23: let copy_ipcs handle setting ipc_ns->user_ns Feb 23: pass ns down rather than taking it from current [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/futex.c')
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c
index bda41571538..6570c459f31 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2418,10 +2418,19 @@ SYSCALL_DEFINE3(get_robust_list, int, pid,
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;
head = p->robust_list;