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| author | Serge E. Hallyn <serge@hallyn.com> | 2011-03-23 16:43:24 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-03-23 19:47:08 -0700 |
| commit | b0e77598f87107001a00b8a4ece9c95e4254ccc4 (patch) | |
| tree | 2738276570e4faa7c92a64521c192f04dca93801 /kernel/futex.c | |
| parent | b515498f5bb5f38fc0e390b4ff7d00b6077de127 (diff) | |
| download | lwn-b0e77598f87107001a00b8a4ece9c95e4254ccc4.tar.gz lwn-b0e77598f87107001a00b8a4ece9c95e4254ccc4.zip | |
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')
| -rw-r--r-- | kernel/futex.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/futex.c b/kernel/futex.c index bda415715382..6570c459f31c 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; +ok: head = p->robust_list; rcu_read_unlock(); } |