Eric Lee / smarc-ti-linux-kernel

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Commit 49f4d8b93ccf9454284b6f524b96c66d8d7fbccc

Authored by Eric W. Biederman
1 parent ae06c7c83f
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

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>

Showing 4 changed files with 19 additions and 9 deletions Side-by-side Diff

include/linux/pid_namespace.h
Diff comments   View file @ 49f4d8b
... ... @@ -31,6 +31,7 @@
31 31 #ifdef CONFIG_BSD_PROCESS_ACCT
32 32 struct bsd_acct_struct *bacct;
33 33 #endif
  34 + struct user_namespace *user_ns;
34 35 kgid_t pid_gid;
35 36 int hide_pid;
36 37 int reboot; /* group exit code if this pidns was rebooted */
... ... @@ -46,7 +47,8 @@
46 47 return ns;
47 48 }
48 49  
49   -extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
  50 +extern struct pid_namespace *copy_pid_ns(unsigned long flags,
  51 + struct user_namespace *user_ns, struct pid_namespace *ns);
50 52 extern void zap_pid_ns_processes(struct pid_namespace *pid_ns);
51 53 extern int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd);
52 54 extern void put_pid_ns(struct pid_namespace *ns);
... ... @@ -59,8 +61,8 @@
59 61 return ns;
60 62 }
61 63  
62   -static inline struct pid_namespace *
63   -copy_pid_ns(unsigned long flags, struct pid_namespace *ns)
  64 +static inline struct pid_namespace *copy_pid_ns(unsigned long flags,
  65 + struct user_namespace *user_ns, struct pid_namespace *ns)
64 66 {
65 67 if (flags & CLONE_NEWPID)
66 68 ns = ERR_PTR(-EINVAL);
... ... @@ -84,7 +84,7 @@
84 84 goto out_ipc;
85 85 }
86 86  
87   - new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
  87 + new_nsp->pid_ns = copy_pid_ns(flags, task_cred_xxx(tsk, user_ns), task_active_pid_ns(tsk));
88 88 if (IS_ERR(new_nsp->pid_ns)) {
89 89 err = PTR_ERR(new_nsp->pid_ns);
90 90 goto out_pid;
... ... @@ -78,6 +78,7 @@
78 78 .last_pid = 0,
79 79 .level = 0,
80 80 .child_reaper = &init_task,
  81 + .user_ns = &init_user_ns,
81 82 };
82 83 EXPORT_SYMBOL_GPL(init_pid_ns);
83 84  
kernel/pid_namespace.c
Diff comments   View file @ 49f4d8b
... ... @@ -10,6 +10,7 @@
10 10  
11 11 #include <linux/pid.h>
12 12 #include <linux/pid_namespace.h>
  13 +#include <linux/user_namespace.h>
13 14 #include <linux/syscalls.h>
14 15 #include <linux/err.h>
15 16 #include <linux/acct.h>
... ... @@ -74,7 +75,8 @@
74 75 /* MAX_PID_NS_LEVEL is needed for limiting size of 'struct pid' */
75 76 #define MAX_PID_NS_LEVEL 32
76 77  
77   -static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_pid_ns)
  78 +static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns,
  79 + struct pid_namespace *parent_pid_ns)
78 80 {
79 81 struct pid_namespace *ns;
80 82 unsigned int level = parent_pid_ns->level + 1;
... ... @@ -102,6 +104,7 @@
102 104 kref_init(&ns->kref);
103 105 ns->level = level;
104 106 ns->parent = get_pid_ns(parent_pid_ns);
  107 + ns->user_ns = get_user_ns(user_ns);
105 108  
106 109 set_bit(0, ns->pidmap[0].page);
107 110 atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1);
... ... @@ -117,6 +120,7 @@
117 120  
118 121 out_put_parent_pid_ns:
119 122 put_pid_ns(parent_pid_ns);
  123 + put_user_ns(user_ns);
120 124 out_free_map:
121 125 kfree(ns->pidmap[0].page);
122 126 out_free:
123 127  
124 128  
... ... @@ -131,16 +135,18 @@
131 135  
132 136 for (i = 0; i < PIDMAP_ENTRIES; i++)
133 137 kfree(ns->pidmap[i].page);
  138 + put_user_ns(ns->user_ns);
134 139 kmem_cache_free(pid_ns_cachep, ns);
135 140 }
136 141  
137   -struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
  142 +struct pid_namespace *copy_pid_ns(unsigned long flags,
  143 + struct user_namespace *user_ns, struct pid_namespace *old_ns)
138 144 {
139 145 if (!(flags & CLONE_NEWPID))
140 146 return get_pid_ns(old_ns);
141 147 if (flags & (CLONE_THREAD|CLONE_PARENT))
142 148 return ERR_PTR(-EINVAL);
143   - return create_pid_namespace(old_ns);
  149 + return create_pid_namespace(user_ns, old_ns);
144 150 }
145 151  
146 152 static void free_pid_ns(struct kref *kref)
147 153  
... ... @@ -239,9 +245,10 @@
239 245 static int pid_ns_ctl_handler(struct ctl_table *table, int write,
240 246 void __user *buffer, size_t *lenp, loff_t *ppos)
241 247 {
  248 + struct pid_namespace *pid_ns = task_active_pid_ns(current);
242 249 struct ctl_table tmp = *table;
243 250  
244   - if (write && !capable(CAP_SYS_ADMIN))
  251 + if (write && !ns_capable(pid_ns->user_ns, CAP_SYS_ADMIN))
245 252 return -EPERM;
246 253  
247 254 /*
... ... @@ -250,7 +257,7 @@
250 257 * it should synchronize its usage with external means.
251 258 */
252 259  
253   - tmp.data = &current->nsproxy->pid_ns->last_pid;
  260 + tmp.data = &pid_ns->last_pid;
254 261 return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
255 262 }
256 263