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Message-ID: <20110619141810.GA3708@albatros>
Date: Sun, 19 Jun 2011 18:18:10 +0400
From: Vasiliy Kulikov <segoon@...nwall.com>
To: kernel-hardening@...ts.openwall.com
Subject: Re: proc info restrictions problem
On Sat, Jun 18, 2011 at 22:28 +0400, Vasiliy Kulikov wrote:
> Another choise - remove hidepid=2 at all.
The patch for hidepid=1 only is as follows:
(tested with /proc exploring and using a sample taskstats program
Documentation/accounting/getdelays.c)
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 5e7cb39..f023e1e 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -52,6 +52,8 @@ show up in /proc/sys/kernel:
- powersave-nap [ PPC only ]
- panic_on_unrecovered_nmi
- printk
+- procinfo_restricted
+- procinfo_restricted_gid
- randomize_va_space
- real-root-dev ==> Documentation/initrd.txt
- reboot-cmd [ SPARC only ]
@@ -403,6 +405,31 @@ Value from 0 - 10000 is allowed.
==============================================================
+procinfo_restricted:
+
+This option defined how much information about processes we want to be
+available for non-owners:
+
+0 - No process information is additionally restricted. Common procfs
+ and taskstats access rules are applied.
+
+1 - Users may not get any statistics or debugging information about any
+ processes, but their own. Process name and command line are
+ restricted too. Users may not access aliens' /proc/<pid>/
+ directories or get any information about aliens' processes via
+ taskstats.
+
+==============================================================
+
+procinfo_restricted_gid:
+
+Defines a group number. All members of this group are allowed to gather
+process' information bypassing procinfo_restricted. If you use identd
+or similar daemon that wants to learn processes information, just add
+the daemon's user to this group.
+
+==============================================================
+
randomize-va-space:
This option can be used to select the type of process address
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 14def99..5fa8d83 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -627,8 +627,19 @@ int proc_setattr(struct dentry *dentry, struct iattr *attr)
return 0;
}
+static int proc_pid_permission(struct inode *inode, int mask,
+ unsigned int flags)
+{
+ struct task_struct *task = get_proc_task(inode);
+
+ if (!procinfo_may_stat_task(task))
+ return -EACCES;
+ return generic_permission(inode, mask, flags, NULL);
+}
+
static const struct inode_operations proc_def_inode_operations = {
.setattr = proc_setattr,
+ .permission = proc_pid_permission,
};
static int mounts_open_common(struct inode *inode, struct file *file,
@@ -1670,6 +1681,7 @@ static const struct inode_operations proc_pid_link_inode_operations = {
.readlink = proc_pid_readlink,
.follow_link = proc_pid_follow_link,
.setattr = proc_setattr,
+ .permission = proc_pid_permission,
};
@@ -2872,6 +2884,7 @@ static const struct inode_operations proc_tgid_base_inode_operations = {
.lookup = proc_tgid_base_lookup,
.getattr = pid_getattr,
.setattr = proc_setattr,
+ .permission = proc_pid_permission,
};
static void proc_flush_task_mnt(struct vfsmount *mnt, pid_t pid, pid_t tgid)
diff --git a/include/linux/capability.h b/include/linux/capability.h
index c421123..cc0bcfe 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -544,7 +544,9 @@ extern bool has_ns_capability(struct task_struct *t,
struct user_namespace *ns, int cap);
extern bool has_capability_noaudit(struct task_struct *t, int cap);
extern bool capable(int cap);
+extern bool task_capable(struct task_struct *task, int cap);
extern bool ns_capable(struct user_namespace *ns, int cap);
+extern bool ns_task_capable(struct task_struct *t, struct user_namespace *ns, int cap);
extern bool task_ns_capable(struct task_struct *t, int cap);
extern bool nsown_capable(int cap);
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 8260799..e910948 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -73,6 +73,7 @@ extern int groups_search(const struct group_info *, gid_t);
((gi)->blocks[(i) / NGROUPS_PER_BLOCK][(i) % NGROUPS_PER_BLOCK])
extern int in_group_p(gid_t);
+extern int task_in_group_p(struct task_struct *task, gid_t grp);
extern int in_egroup_p(gid_t);
/*
diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index 38d1032..ab937c9 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -6,12 +6,27 @@
#include <linux/threads.h>
#include <linux/nsproxy.h>
#include <linux/kref.h>
+#include <linux/ptrace.h>
struct pidmap {
atomic_t nr_free;
void *page;
};
+enum procinfo_restricted {
+ /*
+ * Classical mode, no process information is additionally restricted.
+ */
+ PROCINFO_NONE = 0,
+
+ /*
+ * Users may not learn other users' processess statistics,
+ * debug information, cmdline and comm. Credentials information
+ * is not restricted.
+ */
+ PROCINFO_STATS = 1,
+};
+
#define PIDMAP_ENTRIES ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
struct bsd_acct_struct;
@@ -30,6 +45,8 @@ struct pid_namespace {
#ifdef CONFIG_BSD_PROCESS_ACCT
struct bsd_acct_struct *bacct;
#endif
+ enum procinfo_restricted procinfo_restricted;
+ gid_t procinfo_restricted_gid;
};
extern struct pid_namespace init_pid_ns;
@@ -83,4 +100,51 @@ extern struct pid_namespace *task_active_pid_ns(struct task_struct *tsk);
void pidhash_init(void);
void pidmap_init(void);
+static inline bool procinfo_may_access_task(struct task_struct *tsk, enum procinfo_restricted pr)
+{
+ struct pid_namespace *ns;
+
+ if (current->nsproxy == NULL || current->nsproxy->pid_ns == NULL)
+ return false;
+ ns = current->nsproxy->pid_ns;
+
+ return (ns->procinfo_restricted < pr) ||
+ in_group_p(ns->procinfo_restricted_gid) ||
+ ptrace_may_access(tsk, PTRACE_MODE_READ);
+}
+
+static inline bool procinfo_task_may_access_current(struct task_struct *tsk, enum procinfo_restricted pr)
+{
+ struct pid_namespace *ns;
+
+ if (current->nsproxy == NULL || current->nsproxy->pid_ns == NULL)
+ return false;
+ ns = current->nsproxy->pid_ns;
+
+ return (ns->procinfo_restricted < pr) ||
+ task_in_group_p(tsk, ns->procinfo_restricted_gid) ||
+ ptrace_task_may_access_current(tsk, PTRACE_MODE_READ);
+}
+
+static inline bool procinfo_task_may_stat_current(struct task_struct *tsk)
+{
+ int res;
+ pr_err("check whether %lu may stat %lu...\n",
+ (unsigned long)tsk->pid, (unsigned long)current->pid);
+ res = procinfo_task_may_access_current(tsk, PROCINFO_STATS);
+ pr_err( "%s\n", res ? "yes" : "no");
+ return res;
+}
+
+static inline bool procinfo_may_stat_task(struct task_struct *tsk)
+{
+ int res;
+ pr_err( "check whether %lu may stat %lu...\n",
+ (unsigned long)current->pid,
+ (unsigned long)tsk->pid);
+ res = procinfo_may_access_task(tsk, PROCINFO_STATS);
+ pr_err( "%s\n", res ? "yes" : "no");
+ return res;
+}
+
#endif /* _LINUX_PID_NS_H */
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index 9178d5c..bb59e43 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -116,9 +116,10 @@ extern void exit_ptrace(struct task_struct *tracer);
#define PTRACE_MODE_READ 1
#define PTRACE_MODE_ATTACH 2
/* Returns 0 on success, -errno on denial. */
-extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
+extern int __ptrace_may_access(struct task_struct *who, struct task_struct *task, unsigned int mode);
/* Returns true on success, false on denial. */
extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
+extern bool ptrace_task_may_access_current(struct task_struct *task, unsigned int mode);
static inline int ptrace_reparented(struct task_struct *child)
{
diff --git a/include/linux/security.h b/include/linux/security.h
index 8ce59ef..fb79dd5 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -56,7 +56,8 @@ struct user_namespace;
extern int cap_capable(struct task_struct *tsk, const struct cred *cred,
struct user_namespace *ns, int cap, int audit);
extern int cap_settime(const struct timespec *ts, const struct timezone *tz);
-extern int cap_ptrace_access_check(struct task_struct *child, unsigned int mode);
+extern int cap_ptrace_access_check(struct task_struct *task, struct task_struct *child,
+ unsigned int mode);
extern int cap_ptrace_traceme(struct task_struct *parent);
extern int cap_capget(struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted);
extern int cap_capset(struct cred *new, const struct cred *old,
@@ -1375,7 +1376,9 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
struct security_operations {
char name[SECURITY_NAME_MAX + 1];
- int (*ptrace_access_check) (struct task_struct *child, unsigned int mode);
+ int (*ptrace_access_check) (struct task_struct *task,
+ struct task_struct *child,
+ unsigned int mode);
int (*ptrace_traceme) (struct task_struct *parent);
int (*capget) (struct task_struct *target,
kernel_cap_t *effective,
@@ -1657,6 +1660,8 @@ extern int security_module_enable(struct security_operations *ops);
extern int register_security(struct security_operations *ops);
/* Security operations */
+int security_ptrace_task_access_check(struct task_struct *task,
+ struct task_struct *child, unsigned int mode);
int security_ptrace_access_check(struct task_struct *child, unsigned int mode);
int security_ptrace_traceme(struct task_struct *parent);
int security_capget(struct task_struct *target,
@@ -1667,6 +1672,10 @@ int security_capset(struct cred *new, const struct cred *old,
const kernel_cap_t *effective,
const kernel_cap_t *inheritable,
const kernel_cap_t *permitted);
+int security_task_capable(struct task_struct *task,
+ struct user_namespace *ns,
+ const struct cred *cred,
+ int cap);
int security_capable(struct user_namespace *ns, const struct cred *cred,
int cap);
int security_real_capable(struct task_struct *tsk, struct user_namespace *ns,
@@ -1837,10 +1846,16 @@ static inline int security_init(void)
return 0;
}
+static inline int security_ptrace_task_access_check(struct task_struct *task,
+ struct task_struct *child, unsigned int mode)
+{
+ return cap_ptrace_access_check(task, child, mode);
+}
+
static inline int security_ptrace_access_check(struct task_struct *child,
unsigned int mode)
{
- return cap_ptrace_access_check(child, mode);
+ return cap_ptrace_access_check(current, child, mode);
}
static inline int security_ptrace_traceme(struct task_struct *parent)
@@ -1865,10 +1880,18 @@ static inline int security_capset(struct cred *new,
return cap_capset(new, old, effective, inheritable, permitted);
}
+static inline int security_task_capable(struct task_struct *task,
+ struct user_namespace *ns,
+ const struct cred *cred,
+ int cap)
+{
+ return cap_capable(task, cred, ns, cap, SECURITY_CAP_AUDIT);
+}
+
static inline int security_capable(struct user_namespace *ns,
const struct cred *cred, int cap)
{
- return cap_capable(current, cred, ns, cap, SECURITY_CAP_AUDIT);
+ return security_task_capable(current, ns, cred, cap);
}
static inline int security_real_capable(struct task_struct *tsk, struct user_namespace *ns, int cap)
diff --git a/kernel/capability.c b/kernel/capability.c
index 283c529..93c82fe 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -356,6 +356,30 @@ bool capable(int cap)
}
EXPORT_SYMBOL(capable);
+bool task_capable(struct task_struct *task, int cap)
+{
+ return ns_task_capable(task, &init_user_ns, cap);
+}
+EXPORT_SYMBOL(task_capable);
+
+bool ns_task_capable(struct task_struct *task, struct user_namespace *ns, int cap)
+{
+ if (unlikely(!cap_valid(cap))) {
+ printk(KERN_CRIT "capable() called with invalid cap=%u\n", cap);
+ BUG();
+ }
+
+ rcu_read_lock();
+ if (security_task_capable(task, ns, __task_cred(task), cap) == 0) {
+ rcu_read_unlock();
+ task->flags |= PF_SUPERPRIV;
+ return true;
+ }
+ rcu_read_unlock();
+ return false;
+}
+EXPORT_SYMBOL(ns_task_capable);
+
/**
* ns_capable - Determine if the current task has a superior capability in effect
* @ns: The usernamespace we want the capability in
@@ -369,16 +393,7 @@ EXPORT_SYMBOL(capable);
*/
bool ns_capable(struct user_namespace *ns, int cap)
{
- if (unlikely(!cap_valid(cap))) {
- printk(KERN_CRIT "capable() called with invalid cap=%u\n", cap);
- BUG();
- }
-
- if (security_capable(ns, current_cred(), cap) == 0) {
- current->flags |= PF_SUPERPRIV;
- return true;
- }
- return false;
+ return ns_task_capable(current, ns, cap);
}
EXPORT_SYMBOL(ns_capable);
diff --git a/kernel/groups.c b/kernel/groups.c
index 1cc476d..98ed200 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -268,6 +268,25 @@ int in_group_p(gid_t grp)
EXPORT_SYMBOL(in_group_p);
+/*
+ * Check whether task's fsgid/egid or in the supplemental group..
+ */
+int task_in_group_p(struct task_struct *task, gid_t grp)
+{
+ const struct cred *cred;
+ int retval = 1;
+
+ rcu_read_lock();
+ cred = __task_cred(task);
+
+ if (grp != cred->fsgid)
+ retval = groups_search(cred->group_info, grp);
+ rcu_read_unlock();
+ return retval;
+}
+
+EXPORT_SYMBOL(task_in_group_p);
+
int in_egroup_p(gid_t grp)
{
const struct cred *cred = current_cred();
diff --git a/kernel/pid.c b/kernel/pid.c
index 57a8346..0f692ce 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -78,6 +78,7 @@ struct pid_namespace init_pid_ns = {
.last_pid = 0,
.level = 0,
.child_reaper = &init_task,
+ .procinfo_restricted_gid = -1,
};
EXPORT_SYMBOL_GPL(init_pid_ns);
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index e9c9adc..24b76c2 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -101,6 +101,8 @@ static struct pid_namespace *create_pid_namespace(struct pid_namespace *parent_p
if (err)
goto out_put_parent_pid_ns;
+ ns->procinfo_restricted_gid = -1;
+
return ns;
out_put_parent_pid_ns:
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 2df1157..ccbec73 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -132,9 +132,9 @@ int ptrace_check_attach(struct task_struct *child, int kill)
return ret;
}
-int __ptrace_may_access(struct task_struct *task, unsigned int mode)
+int __ptrace_may_access(struct task_struct *who, struct task_struct *task, unsigned int mode)
{
- const struct cred *cred = current_cred(), *tcred;
+ const struct cred *cred, *tcred;
/* May we inspect the given task?
* This check is used both for attaching with ptrace
@@ -146,9 +146,10 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode)
*/
int dumpable = 0;
/* Don't let security modules deny introspection */
- if (task == current)
+ if (task == who)
return 0;
rcu_read_lock();
+ cred = __task_cred(who);
tcred = __task_cred(task);
if (cred->user->user_ns == tcred->user->user_ns &&
(cred->uid == tcred->euid &&
@@ -158,7 +159,7 @@ int __ptrace_may_access(struct task_struct *task, unsigned int mode)
cred->gid == tcred->sgid &&
cred->gid == tcred->gid))
goto ok;
- if (ns_capable(tcred->user->user_ns, CAP_SYS_PTRACE))
+ if (ns_task_capable(who, tcred->user->user_ns, CAP_SYS_PTRACE))
goto ok;
rcu_read_unlock();
return -EPERM;
@@ -167,17 +168,32 @@ ok:
smp_rmb();
if (task->mm)
dumpable = get_dumpable(task->mm);
- if (!dumpable && !task_ns_capable(task, CAP_SYS_PTRACE))
+ if (!dumpable &&
+ !ns_task_capable(who, task_cred_xxx(task, user)->user_ns,
+ CAP_SYS_PTRACE))
return -EPERM;
- return security_ptrace_access_check(task, mode);
+ return security_ptrace_task_access_check(who, task, mode);
}
bool ptrace_may_access(struct task_struct *task, unsigned int mode)
{
int err;
task_lock(task);
- err = __ptrace_may_access(task, mode);
+ err = __ptrace_may_access(current, task, mode);
+ task_unlock(task);
+ return !err;
+}
+
+/*
+ * Generic task_may_access_task cannot be implemented because we have to
+ * hold task_locks of both tasks. It would lead to a deadlock.
+ */
+bool ptrace_task_may_access_current(struct task_struct *task, unsigned int mode)
+{
+ int err;
+ task_lock(task);
+ err = __ptrace_may_access(task, current, mode);
task_unlock(task);
return !err;
}
@@ -205,7 +221,7 @@ static int ptrace_attach(struct task_struct *task)
goto out;
task_lock(task);
- retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
+ retval = __ptrace_may_access(current, task, PTRACE_MODE_ATTACH);
task_unlock(task);
if (retval)
goto unlock_creds;
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index f175d98..da95aab 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -57,6 +57,7 @@
#include <linux/pipe_fs_i.h>
#include <linux/oom.h>
#include <linux/kmod.h>
+#include <linux/pid_namespace.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
@@ -984,6 +985,22 @@ static struct ctl_table kern_table[] = {
.proc_handler = proc_dointvec,
},
#endif
+ {
+ .procname = "procinfo_restricted",
+ .data = &init_pid_ns.procinfo_restricted,
+ .maxlen = sizeof(init_pid_ns.procinfo_restricted),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+ {
+ .procname = "procinfo_restricted_gid",
+ .data = &init_pid_ns.procinfo_restricted_gid,
+ .maxlen = sizeof(init_pid_ns.procinfo_restricted_gid),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
{ }
};
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index 9ffea36..bec6258 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -27,6 +27,7 @@
#include <linux/cgroup.h>
#include <linux/fs.h>
#include <linux/file.h>
+#include <linux/pid_namespace.h>
#include <net/genetlink.h>
#include <asm/atomic.h>
@@ -132,6 +133,7 @@ static void send_cpu_listeners(struct sk_buff *skb,
struct sk_buff *skb_next, *skb_cur = skb;
void *reply = genlmsg_data(genlhdr);
int rc, delcount = 0;
+ struct task_struct *tsk;
rc = genlmsg_end(skb, reply);
if (rc < 0) {
@@ -143,6 +145,15 @@ static void send_cpu_listeners(struct sk_buff *skb,
down_read(&listeners->sem);
list_for_each_entry(s, &listeners->list, list) {
skb_next = NULL;
+
+ rcu_read_lock();
+ tsk = find_task_by_vpid(s->pid);
+ if (!tsk || !procinfo_task_may_stat_current(tsk)) {
+ rcu_read_unlock();
+ continue;
+ }
+ rcu_read_unlock();
+
if (!list_is_last(&s->list, &listeners->list)) {
skb_next = skb_clone(skb_cur, GFP_KERNEL);
if (!skb_next)
@@ -199,14 +210,20 @@ static void fill_stats(struct task_struct *tsk, struct taskstats *stats)
static int fill_stats_for_pid(pid_t pid, struct taskstats *stats)
{
struct task_struct *tsk;
+ int err = -ESRCH;
rcu_read_lock();
tsk = find_task_by_vpid(pid);
+ if (tsk && !procinfo_may_stat_task(tsk)) {
+ tsk = NULL;
+ err = -EACCES;
+ }
+
if (tsk)
get_task_struct(tsk);
rcu_read_unlock();
if (!tsk)
- return -ESRCH;
+ return err;
fill_stats(tsk, stats);
put_task_struct(tsk);
return 0;
@@ -217,6 +234,7 @@ static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
struct task_struct *tsk, *first;
unsigned long flags;
int rc = -ESRCH;
+ bool filled;
/*
* Add additional stats from live tasks except zombie thread group
@@ -228,15 +246,29 @@ static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
if (!first || !lock_task_sighand(first, &flags))
goto out;
- if (first->signal->stats)
+ if (first->signal->stats && procinfo_may_stat_task(first)) {
memcpy(stats, first->signal->stats, sizeof(*stats));
- else
+ filled = true;
+ } else {
memset(stats, 0, sizeof(*stats));
+ filled = false;
+ }
tsk = first;
do {
if (tsk->exit_state)
continue;
+
+ /*
+ * As there could be tasks with different creds in the same
+ * process group, we should check perms for each task
+ * separately.
+ */
+ if (!procinfo_may_stat_task(tsk))
+ continue;
+
+ filled = true;
+
/*
* Accounting subsystem can call its functions here to
* fill in relevant parts of struct taskstsats as follows
@@ -250,7 +282,11 @@ static int fill_stats_for_tgid(pid_t tgid, struct taskstats *stats)
} while_each_thread(first, tsk);
unlock_task_sighand(first, &flags);
- rc = 0;
+
+ if (filled)
+ rc = 0;
+ else
+ rc = -EACCES;
out:
rcu_read_unlock();
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index ec1bcec..dc3a4aa 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -93,14 +93,14 @@ static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
aa_dup_task_context(new_cxt, old_cxt);
}
-static int apparmor_ptrace_access_check(struct task_struct *child,
- unsigned int mode)
+static int apparmor_ptrace_access_check(struct task_struct *task,
+ struct task_struct *child, unsigned int mode)
{
- int error = cap_ptrace_access_check(child, mode);
+ int error = cap_ptrace_access_check(task, child, mode);
if (error)
return error;
- return aa_ptrace(current, child, mode);
+ return aa_ptrace(task, child, mode);
}
static int apparmor_ptrace_traceme(struct task_struct *parent)
diff --git a/security/commoncap.c b/security/commoncap.c
index a93b3b7..31ca991 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -136,18 +136,19 @@ int cap_settime(const struct timespec *ts, const struct timezone *tz)
* Determine whether a process may access another, returning 0 if permission
* granted, -ve if denied.
*/
-int cap_ptrace_access_check(struct task_struct *child, unsigned int mode)
+int cap_ptrace_access_check(struct task_struct *task, struct task_struct *child,
+ unsigned int mode)
{
int ret = 0;
const struct cred *cred, *child_cred;
rcu_read_lock();
- cred = current_cred();
+ cred = __task_cred(task);
child_cred = __task_cred(child);
if (cred->user->user_ns == child_cred->user->user_ns &&
cap_issubset(child_cred->cap_permitted, cred->cap_permitted))
goto out;
- if (ns_capable(child_cred->user->user_ns, CAP_SYS_PTRACE))
+ if (ns_task_capable(task, child_cred->user->user_ns, CAP_SYS_PTRACE))
goto out;
ret = -EPERM;
out:
diff --git a/security/security.c b/security/security.c
index 4ba6d4c..0760e81 100644
--- a/security/security.c
+++ b/security/security.c
@@ -127,9 +127,15 @@ int __init register_security(struct security_operations *ops)
/* Security operations */
+int security_ptrace_task_access_check(struct task_struct *task,
+ struct task_struct *child, unsigned int mode)
+{
+ return security_ops->ptrace_access_check(task, child, mode);
+}
+
int security_ptrace_access_check(struct task_struct *child, unsigned int mode)
{
- return security_ops->ptrace_access_check(child, mode);
+ return security_ops->ptrace_access_check(current, child, mode);
}
int security_ptrace_traceme(struct task_struct *parent)
@@ -154,11 +160,16 @@ int security_capset(struct cred *new, const struct cred *old,
effective, inheritable, permitted);
}
+int security_task_capable(struct task_struct *task, struct user_namespace *ns,
+ const struct cred *cred, int cap)
+{
+ return security_ops->capable(task, cred, ns, cap, SECURITY_CAP_AUDIT);
+}
+
int security_capable(struct user_namespace *ns, const struct cred *cred,
int cap)
{
- return security_ops->capable(current, cred, ns, cap,
- SECURITY_CAP_AUDIT);
+ return security_task_capable(current, ns, cred, cap);
}
int security_real_capable(struct task_struct *tsk, struct user_namespace *ns,
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 20219ef..0130255 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1804,23 +1804,22 @@ static inline u32 open_file_to_av(struct file *file)
}
/* Hook functions begin here. */
-
-static int selinux_ptrace_access_check(struct task_struct *child,
- unsigned int mode)
+static int selinux_ptrace_access_check(struct task_struct *task,
+ struct task_struct *child, unsigned int mode)
{
int rc;
- rc = cap_ptrace_access_check(child, mode);
+ rc = cap_ptrace_access_check(task, child, mode);
if (rc)
return rc;
if (mode == PTRACE_MODE_READ) {
- u32 sid = current_sid();
+ u32 sid = task_sid(task);
u32 csid = task_sid(child);
return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
}
- return current_has_perm(child, PROCESS__PTRACE);
+ return task_has_perm(task, child, PROCESS__PTRACE);
}
static int selinux_ptrace_traceme(struct task_struct *parent)
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 2b6c6a5..4d9fb0f 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -199,6 +199,7 @@ struct inode_smack *new_inode_smack(char *);
*/
int smk_access_entry(char *, char *, struct list_head *);
int smk_access(char *, char *, int, struct smk_audit_info *);
+int smk_taskacc(struct task_struct *, char *, u32, struct smk_audit_info *);
int smk_curacc(char *, u32, struct smk_audit_info *);
int smack_to_cipso(const char *, struct smack_cipso *);
void smack_from_cipso(u32, char *, char *);
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 9637e10..766dccd 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -201,7 +201,8 @@ out_audit:
}
/**
- * smk_curacc - determine if current has a specific access to an object
+ * smk_curacc - determine if subject has a specific access to an object
+ * @task: a pointer to the subject's task struct
* @obj_label: a pointer to the object's Smack label
* @mode: the access requested, in "MAY" format
* @a : common audit data
@@ -211,9 +212,9 @@ out_audit:
* non zero otherwise. It allows that current may have the capability
* to override the rules.
*/
-int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
+int smk_taskacc(struct task_struct *task, char *obj_label, u32 mode, struct smk_audit_info *a)
{
- struct task_smack *tsp = current_security();
+ struct task_smack *tsp = task_cred_xxx(task, security);
char *sp = smk_of_task(tsp);
int may;
int rc;
@@ -243,7 +244,7 @@ int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
if (smack_onlycap != NULL && smack_onlycap != sp)
goto out_audit;
- if (capable(CAP_MAC_OVERRIDE))
+ if (task_capable(task, CAP_MAC_OVERRIDE))
rc = 0;
out_audit:
@@ -254,6 +255,22 @@ out_audit:
return rc;
}
+/**
+ * smk_curacc - determine if current has a specific access to an object
+ * @obj_label: a pointer to the object's Smack label
+ * @mode: the access requested, in "MAY" format
+ * @a : common audit data
+ *
+ * This function checks the current subject label/object label pair
+ * in the access rule list and returns 0 if the access is permitted,
+ * non zero otherwise. It allows that current may have the capability
+ * to override the rules.
+ */
+int smk_curacc(char *obj_label, u32 mode, struct smk_audit_info *a)
+{
+ return smk_taskacc(current, obj_label, mode, a);
+}
+
#ifdef CONFIG_AUDIT
/**
* smack_str_from_perm : helper to transalate an int to a
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 9831a39..ee1c5cb 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -149,13 +149,14 @@ static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
*
* Do the capability checks, and require read and write.
*/
-static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
+static int smack_ptrace_access_check(struct task_struct *task,
+ struct task_struct *ctp, unsigned int mode)
{
int rc;
struct smk_audit_info ad;
char *tsp;
- rc = cap_ptrace_access_check(ctp, mode);
+ rc = cap_ptrace_access_check(task, ctp, mode);
if (rc != 0)
return rc;
@@ -163,7 +164,7 @@ static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, ctp);
- rc = smk_curacc(tsp, MAY_READWRITE, &ad);
+ rc = smk_taskacc(task, tsp, MAY_READWRITE, &ad);
return rc;
}
--
Vasiliy Kulikov
http://www.openwall.com - bringing security into open computing environments
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