diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2012-08-02 04:25:10 -0700 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-11-19 05:57:31 -0800 |
| commit | 49f4d8b93ccf9454284b6f524b96c66d8d7fbccc (patch) | |
| tree | 06540b59a9d302687fd0519239729c1612d0e2b7 /kernel/pid_namespace.c | |
| parent | ae06c7c83fc6e97ba247a261921c101960f3d28f (diff) | |
pidns: Capture the user namespace and filter ns_last_pid
- Capture the the user namespace that creates the pid namespace
- Use that user namespace to test if it is ok to write to
/proc/sys/kernel/ns_last_pid.
Zhao Hongjiang <zhaohongjiang@huawei.com> noticed I was missing a put_user_ns
in when destroying a pid_ns. I have foloded his patch into this one
so that bisects will work properly.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel/pid_namespace.c')
| -rw-r--r-- | kernel/pid_namespace.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 7b07cc0dfb75..b2604950aa50 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -10,6 +10,7 @@ #include <linux/pid.h> #include <linux/pid_namespace.h> +#include <linux/user_namespace.h> #include <linux/syscalls.h> #include <linux/err.h> #include <linux/acct.h> @@ -74,7 +75,8 @@ err_alloc: /* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */ #define MAX_PID_NS_LEVEL 32 -static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_pid_ns) +static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns, + struct pid_namespace *parent_pid_ns) { struct pid_namespace *ns; unsigned int level = parent_pid_ns->level + 1; @@ -102,6 +104,7 @@ static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_p kref_init(&ns->kref); ns->level = level; ns->parent = get_pid_ns(parent_pid_ns); + ns->user_ns = get_user_ns(user_ns); set_bit(0, ns->pidmap[0].page); atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1); @@ -117,6 +120,7 @@ static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_p out_put_parent_pid_ns: put_pid_ns(parent_pid_ns); + put_user_ns(user_ns); out_free_map: kfree(ns->pidmap[0].page); out_free: @@ -131,16 +135,18 @@ static void destroy_pid_namespace(struct pid_namespace *ns) for (i = 0; i < PIDMAP_ENTRIES; i++) kfree(ns->pidmap[i].page); + put_user_ns(ns->user_ns); kmem_cache_free(pid_ns_cachep, ns); } -struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns) +struct pid_namespace *copy_pid_ns(unsigned long flags, + struct user_namespace *user_ns, struct pid_namespace *old_ns) { if (!(flags & CLONE_NEWPID)) return get_pid_ns(old_ns); if (flags & (CLONE_THREAD|CLONE_PARENT)) return ERR_PTR(-EINVAL); - return create_pid_namespace(old_ns); + return create_pid_namespace(user_ns, old_ns); } static void free_pid_ns(struct kref *kref) @@ -239,9 +245,10 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) static int pid_ns_ctl_handler(struct ctl_table *table, int write, void __user *buffer, size_t *lenp, loff_t *ppos) { + struct pid_namespace *pid_ns = task_active_pid_ns(current); struct ctl_table tmp = *table; - if (write && !capable(CAP_SYS_ADMIN)) + if (write && !ns_capable(pid_ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; /* @@ -250,7 +257,7 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write, * it should synchronize its usage with external means. */ - tmp.data = ¤t->nsproxy->pid_ns->last_pid; + tmp.data = &pid_ns->last_pid; return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos); } |