[kernel/f16] /proc/pid/* information leak (rhbz 782686)
Josh Boyer
jwboyer at fedoraproject.org
Wed Jan 18 20:06:41 UTC 2012
commit 872d2983fcd65973adc610246001f9276ca4c5b1
Author: Josh Boyer <jwboyer at redhat.com>
Date: Wed Jan 18 13:22:40 2012 -0500
/proc/pid/* information leak (rhbz 782686)
kernel.spec | 11 +
...null-pointer-deref-in-proc_pid_permission.patch | 44 +++
procfs-add-hidepid-and-gid-mount-options.patch | 342 ++++++++++++++++++++
procfs-parse-mount-options.patch | 173 ++++++++++
4 files changed, 570 insertions(+), 0 deletions(-)
---
diff --git a/kernel.spec b/kernel.spec
index d77ba82..bda9dbf 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -869,6 +869,11 @@ Patch21077: 01-block-add-and-use-scsi_blk_cmd_ioctl.patch
Patch21078: 02-block-fail-SCSI-passthrough-ioctls-on-partition-devs.patch
Patch21079: 03-dm-dont-fwd-ioctls-from-LVs-to-underlying-dev.patch
+#rhbz 782686
+Patch21082: procfs-parse-mount-options.patch
+Patch21083: procfs-add-hidepid-and-gid-mount-options.patch
+Patch21084: proc-fix-null-pointer-deref-in-proc_pid_permission.patch
+
#rhbz 782681
Patch21085: proc-clean-up-and-fix-proc-pid-mem-handling.patch
@@ -1608,6 +1613,11 @@ ApplyPatch 01-block-add-and-use-scsi_blk_cmd_ioctl.patch
ApplyPatch 02-block-fail-SCSI-passthrough-ioctls-on-partition-devs.patch
ApplyPatch 03-dm-dont-fwd-ioctls-from-LVs-to-underlying-dev.patch
+#rhbz 782686
+ApplyPatch procfs-parse-mount-options.patch
+ApplyPatch procfs-add-hidepid-and-gid-mount-options.patch
+ApplyPatch proc-fix-null-pointer-deref-in-proc_pid_permission.patch
+
#rhbz 782681
ApplyPatch proc-clean-up-and-fix-proc-pid-mem-handling.patch
@@ -2390,6 +2400,7 @@ fi
%changelog
* Wed Jan 18 2012 Josh Boyer <jwboyer at redhat.com> 3.1.10-1
- Linux 3.1.10
+- /proc/pid/* information leak (rhbz 782686)
- CVE-2012-0056 proc: clean up and fix /proc/<pid>/mem (rhbz 782681)
- loop: prevent information leak after failed read (rhbz 782687)
diff --git a/proc-fix-null-pointer-deref-in-proc_pid_permission.patch b/proc-fix-null-pointer-deref-in-proc_pid_permission.patch
new file mode 100644
index 0000000..62d2fb2
--- /dev/null
+++ b/proc-fix-null-pointer-deref-in-proc_pid_permission.patch
@@ -0,0 +1,44 @@
+From a2ef990ab5a6705a356d146dd773a3b359787497 Mon Sep 17 00:00:00 2001
+From: Xiaotian Feng <xtfeng at gmail.com>
+Date: Thu, 12 Jan 2012 17:17:08 -0800
+Subject: [PATCH] proc: fix null pointer deref in proc_pid_permission()
+
+get_proc_task() can fail to search the task and return NULL,
+put_task_struct() will then bomb the kernel with following oops:
+
+ BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
+ IP: [<ffffffff81217d34>] proc_pid_permission+0x64/0xe0
+ PGD 112075067 PUD 112814067 PMD 0
+ Oops: 0002 [#1] PREEMPT SMP
+
+This is a regression introduced by commit 0499680a ("procfs: add hidepid=
+and gid= mount options"). The kernel should return -ESRCH if
+get_proc_task() failed.
+
+Signed-off-by: Xiaotian Feng <dannyfeng at tencent.com>
+Cc: Al Viro <viro at zeniv.linux.org.uk>
+Cc: Vasiliy Kulikov <segoon at openwall.com>
+Cc: Stephen Wilson <wilsons at start.ca>
+Acked-by: David Rientjes <rientjes at google.com>
+Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+---
+ fs/proc/base.c | 2 ++
+ 1 files changed, 2 insertions(+), 0 deletions(-)
+
+diff --git a/fs/proc/base.c b/fs/proc/base.c
+index 8173dfd..5485a53 100644
+--- a/fs/proc/base.c
++++ b/fs/proc/base.c
+@@ -654,6 +654,8 @@ static int proc_pid_permission(struct inode *inode, int mask)
+ bool has_perms;
+
+ task = get_proc_task(inode);
++ if (!task)
++ return -ESRCH;
+ has_perms = has_pid_permissions(pid, task, 1);
+ put_task_struct(task);
+
+--
+1.7.7.5
+
diff --git a/procfs-add-hidepid-and-gid-mount-options.patch b/procfs-add-hidepid-and-gid-mount-options.patch
new file mode 100644
index 0000000..24156b0
--- /dev/null
+++ b/procfs-add-hidepid-and-gid-mount-options.patch
@@ -0,0 +1,342 @@
+From 0499680a42141d86417a8fbaa8c8db806bea1201 Mon Sep 17 00:00:00 2001
+From: Vasiliy Kulikov <segooon at gmail.com>
+Date: Tue, 10 Jan 2012 15:11:31 -0800
+Subject: [PATCH] procfs: add hidepid= and gid= mount options
+
+Add support for mount options to restrict access to /proc/PID/
+directories. The default backward-compatible "relaxed" behaviour is left
+untouched.
+
+The first mount option is called "hidepid" and its value defines how much
+info about processes we want to be available for non-owners:
+
+hidepid=0 (default) means the old behavior - anybody may read all
+world-readable /proc/PID/* files.
+
+hidepid=1 means users may not access any /proc/<pid>/ directories, but
+their own. Sensitive files like cmdline, sched*, status are now protected
+against other users. As permission checking done in proc_pid_permission()
+and files' permissions are left untouched, programs expecting specific
+files' modes are not confused.
+
+hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other
+users. It doesn't mean that it hides whether a process exists (it can be
+learned by other means, e.g. by kill -0 $PID), but it hides process' euid
+and egid. It compicates intruder's task of gathering info about running
+processes, whether some daemon runs with elevated privileges, whether
+another user runs some sensitive program, whether other users run any
+program at all, etc.
+
+gid=XXX defines a group that will be able to gather all processes' info
+(as in hidepid=0 mode). This group should be used instead of putting
+nonroot user in sudoers file or something. However, untrusted users (like
+daemons, etc.) which are not supposed to monitor the tasks in the whole
+system should not be added to the group.
+
+hidepid=1 or higher is designed to restrict access to procfs files, which
+might reveal some sensitive private information like precise keystrokes
+timings:
+
+http://www.openwall.com/lists/oss-security/2011/11/05/3
+
+hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and
+conky gracefully handle EPERM/ENOENT and behave as if the current user is
+the only user running processes. pstree shows the process subtree which
+contains "pstree" process.
+
+Note: the patch doesn't deal with setuid/setgid issues of keeping
+preopened descriptors of procfs files (like
+https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked
+information like the scheduling counters of setuid apps doesn't threaten
+anybody's privacy - only the user started the setuid program may read the
+counters.
+
+Signed-off-by: Vasiliy Kulikov <segoon at openwall.com>
+Cc: Alexey Dobriyan <adobriyan at gmail.com>
+Cc: Al Viro <viro at zeniv.linux.org.uk>
+Cc: Randy Dunlap <rdunlap at xenotime.net>
+Cc: "H. Peter Anvin" <hpa at zytor.com>
+Cc: Greg KH <greg at kroah.com>
+Cc: Theodore Tso <tytso at MIT.EDU>
+Cc: Alan Cox <alan at lxorguk.ukuu.org.uk>
+Cc: James Morris <jmorris at namei.org>
+Cc: Oleg Nesterov <oleg at redhat.com>
+Cc: Hugh Dickins <hughd at google.com>
+Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+---
+ Documentation/filesystems/proc.txt | 39 ++++++++++++++++++++
+ fs/proc/base.c | 69 +++++++++++++++++++++++++++++++++++-
+ fs/proc/inode.c | 8 ++++
+ fs/proc/root.c | 21 +++++++++--
+ include/linux/pid_namespace.h | 2 +
+ 5 files changed, 135 insertions(+), 4 deletions(-)
+
+diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
+index 0ec91f0..12fee13 100644
+--- a/Documentation/filesystems/proc.txt
++++ b/Documentation/filesystems/proc.txt
+@@ -41,6 +41,8 @@ Table of Contents
+ 3.5 /proc/<pid>/mountinfo - Information about mounts
+ 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
+
++ 4 Configuring procfs
++ 4.1 Mount options
+
+ ------------------------------------------------------------------------------
+ Preface
+@@ -1542,3 +1544,40 @@ a task to set its own or one of its thread siblings comm value. The comm value
+ is limited in size compared to the cmdline value, so writing anything longer
+ then the kernel's TASK_COMM_LEN (currently 16 chars) will result in a truncated
+ comm value.
++
++
++------------------------------------------------------------------------------
++Configuring procfs
++------------------------------------------------------------------------------
++
++4.1 Mount options
++---------------------
++
++The following mount options are supported:
++
++ hidepid= Set /proc/<pid>/ access mode.
++ gid= Set the group authorized to learn processes information.
++
++hidepid=0 means classic mode - everybody may access all /proc/<pid>/ directories
++(default).
++
++hidepid=1 means users may not access any /proc/<pid>/ directories but their
++own. Sensitive files like cmdline, sched*, status are now protected against
++other users. This makes it impossible to learn whether any user runs
++specific program (given the program doesn't reveal itself by its behaviour).
++As an additional bonus, as /proc/<pid>/cmdline is unaccessible for other users,
++poorly written programs passing sensitive information via program arguments are
++now protected against local eavesdroppers.
++
++hidepid=2 means hidepid=1 plus all /proc/<pid>/ will be fully invisible to other
++users. It doesn't mean that it hides a fact whether a process with a specific
++pid value exists (it can be learned by other means, e.g. by "kill -0 $PID"),
++but it hides process' uid and gid, which may be learned by stat()'ing
++/proc/<pid>/ otherwise. It greatly complicates an intruder's task of gathering
++information about running processes, whether some daemon runs with elevated
++privileges, whether other user runs some sensitive program, whether other users
++run any program at all, etc.
++
++gid= defines a group authorized to learn processes information otherwise
++prohibited by hidepid=. If you use some daemon like identd which needs to learn
++information about processes information, just add identd to this group.
+diff --git a/fs/proc/base.c b/fs/proc/base.c
+index 4d755fe..8173dfd 100644
+--- a/fs/proc/base.c
++++ b/fs/proc/base.c
+@@ -631,6 +631,50 @@ int proc_setattr(struct dentry *dentry, struct iattr *attr)
+ return 0;
+ }
+
++/*
++ * May current process learn task's sched/cmdline info (for hide_pid_min=1)
++ * or euid/egid (for hide_pid_min=2)?
++ */
++static bool has_pid_permissions(struct pid_namespace *pid,
++ struct task_struct *task,
++ int hide_pid_min)
++{
++ if (pid->hide_pid < hide_pid_min)
++ return true;
++ if (in_group_p(pid->pid_gid))
++ return true;
++ return ptrace_may_access(task, PTRACE_MODE_READ);
++}
++
++
++static int proc_pid_permission(struct inode *inode, int mask)
++{
++ struct pid_namespace *pid = inode->i_sb->s_fs_info;
++ struct task_struct *task;
++ bool has_perms;
++
++ task = get_proc_task(inode);
++ has_perms = has_pid_permissions(pid, task, 1);
++ put_task_struct(task);
++
++ if (!has_perms) {
++ if (pid->hide_pid == 2) {
++ /*
++ * Let's make getdents(), stat(), and open()
++ * consistent with each other. If a process
++ * may not stat() a file, it shouldn't be seen
++ * in procfs at all.
++ */
++ return -ENOENT;
++ }
++
++ return -EPERM;
++ }
++ return generic_permission(inode, mask);
++}
++
++
++
+ static const struct inode_operations proc_def_inode_operations = {
+ .setattr = proc_setattr,
+ };
+@@ -1615,6 +1659,7 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+ struct inode *inode = dentry->d_inode;
+ struct task_struct *task;
+ const struct cred *cred;
++ struct pid_namespace *pid = dentry->d_sb->s_fs_info;
+
+ generic_fillattr(inode, stat);
+
+@@ -1623,6 +1668,14 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+ stat->gid = 0;
+ task = pid_task(proc_pid(inode), PIDTYPE_PID);
+ if (task) {
++ if (!has_pid_permissions(pid, task, 2)) {
++ rcu_read_unlock();
++ /*
++ * This doesn't prevent learning whether PID exists,
++ * it only makes getattr() consistent with readdir().
++ */
++ return -ENOENT;
++ }
+ if ((inode->i_mode == (S_IFDIR|S_IRUGO|S_IXUGO)) ||
+ task_dumpable(task)) {
+ cred = __task_cred(task);
+@@ -3119,6 +3172,7 @@ 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)
+@@ -3322,6 +3376,12 @@ static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldi
+ proc_pid_instantiate, iter.task, NULL);
+ }
+
++static int fake_filldir(void *buf, const char *name, int namelen,
++ loff_t offset, u64 ino, unsigned d_type)
++{
++ return 0;
++}
++
+ /* for the /proc/ directory itself, after non-process stuff has been done */
+ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
+ {
+@@ -3329,6 +3389,7 @@ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
+ struct task_struct *reaper;
+ struct tgid_iter iter;
+ struct pid_namespace *ns;
++ filldir_t __filldir;
+
+ if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET)
+ goto out_no_task;
+@@ -3350,8 +3411,13 @@ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir)
+ for (iter = next_tgid(ns, iter);
+ iter.task;
+ iter.tgid += 1, iter = next_tgid(ns, iter)) {
++ if (has_pid_permissions(ns, iter.task, 2))
++ __filldir = filldir;
++ else
++ __filldir = fake_filldir;
++
+ filp->f_pos = iter.tgid + TGID_OFFSET;
+- if (proc_pid_fill_cache(filp, dirent, filldir, iter) < 0) {
++ if (proc_pid_fill_cache(filp, dirent, __filldir, iter) < 0) {
+ put_task_struct(iter.task);
+ goto out;
+ }
+@@ -3686,6 +3752,7 @@ static const struct inode_operations proc_task_inode_operations = {
+ .lookup = proc_task_lookup,
+ .getattr = proc_task_getattr,
+ .setattr = proc_setattr,
++ .permission = proc_pid_permission,
+ };
+
+ static const struct file_operations proc_task_operations = {
+diff --git a/fs/proc/inode.c b/fs/proc/inode.c
+index 27c762f..84fd323 100644
+--- a/fs/proc/inode.c
++++ b/fs/proc/inode.c
+@@ -106,6 +106,14 @@ void __init proc_init_inodecache(void)
+
+ static int proc_show_options(struct seq_file *seq, struct dentry *root)
+ {
++ struct super_block *sb = root->d_sb;
++ struct pid_namespace *pid = sb->s_fs_info;
++
++ if (pid->pid_gid)
++ seq_printf(seq, ",gid=%lu", (unsigned long)pid->pid_gid);
++ if (pid->hide_pid != 0)
++ seq_printf(seq, ",hidepid=%u", pid->hide_pid);
++
+ return 0;
+ }
+
+diff --git a/fs/proc/root.c b/fs/proc/root.c
+index 6a8ac1d..46a15d8 100644
+--- a/fs/proc/root.c
++++ b/fs/proc/root.c
+@@ -38,10 +38,12 @@ static int proc_set_super(struct super_block *sb, void *data)
+ }
+
+ enum {
+- Opt_err,
++ Opt_gid, Opt_hidepid, Opt_err,
+ };
+
+ static const match_table_t tokens = {
++ {Opt_hidepid, "hidepid=%u"},
++ {Opt_gid, "gid=%u"},
+ {Opt_err, NULL},
+ };
+
+@@ -49,8 +51,7 @@ static int proc_parse_options(char *options, struct pid_namespace *pid)
+ {
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+-
+- pr_debug("proc: options = %s\n", options);
++ int option;
+
+ if (!options)
+ return 1;
+@@ -63,6 +64,20 @@ static int proc_parse_options(char *options, struct pid_namespace *pid)
+ args[0].to = args[0].from = 0;
+ token = match_token(p, tokens, args);
+ switch (token) {
++ case Opt_gid:
++ if (match_int(&args[0], &option))
++ return 0;
++ pid->pid_gid = option;
++ break;
++ case Opt_hidepid:
++ if (match_int(&args[0], &option))
++ return 0;
++ if (option < 0 || option > 2) {
++ pr_err("proc: hidepid value must be between 0 and 2.\n");
++ return 0;
++ }
++ pid->hide_pid = option;
++ break;
+ default:
+ pr_err("proc: unrecognized mount option \"%s\" "
+ "or missing value\n", p);
+diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
+index 38d1032..e7cf666 100644
+--- a/include/linux/pid_namespace.h
++++ b/include/linux/pid_namespace.h
+@@ -30,6 +30,8 @@ struct pid_namespace {
+ #ifdef CONFIG_BSD_PROCESS_ACCT
+ struct bsd_acct_struct *bacct;
+ #endif
++ gid_t pid_gid;
++ int hide_pid;
+ };
+
+ extern struct pid_namespace init_pid_ns;
+--
+1.7.7.5
+
diff --git a/procfs-parse-mount-options.patch b/procfs-parse-mount-options.patch
new file mode 100644
index 0000000..99684c4
--- /dev/null
+++ b/procfs-parse-mount-options.patch
@@ -0,0 +1,173 @@
+From 97412950b10e64f347aec4a9b759395c2465adf6 Mon Sep 17 00:00:00 2001
+From: Vasiliy Kulikov <segooon at gmail.com>
+Date: Tue, 10 Jan 2012 15:11:27 -0800
+Subject: [PATCH] procfs: parse mount options
+
+Add support for procfs mount options. Actual mount options are coming in
+the next patches.
+
+Signed-off-by: Vasiliy Kulikov <segoon at openwall.com>
+Cc: Alexey Dobriyan <adobriyan at gmail.com>
+Cc: Al Viro <viro at zeniv.linux.org.uk>
+Cc: Randy Dunlap <rdunlap at xenotime.net>
+Cc: "H. Peter Anvin" <hpa at zytor.com>
+Cc: Greg KH <greg at kroah.com>
+Cc: Theodore Tso <tytso at MIT.EDU>
+Cc: Alan Cox <alan at lxorguk.ukuu.org.uk>
+Cc: James Morris <jmorris at namei.org>
+Cc: Oleg Nesterov <oleg at redhat.com>
+Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
+---
+ fs/proc/inode.c | 10 +++++++++
+ fs/proc/internal.h | 1 +
+ fs/proc/root.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++-
+ 3 files changed, 64 insertions(+), 2 deletions(-)
+
+diff --git a/fs/proc/inode.c b/fs/proc/inode.c
+index 51a1766..27c762f 100644
+--- a/fs/proc/inode.c
++++ b/fs/proc/inode.c
+@@ -7,6 +7,7 @@
+ #include <linux/time.h>
+ #include <linux/proc_fs.h>
+ #include <linux/kernel.h>
++#include <linux/pid_namespace.h>
+ #include <linux/mm.h>
+ #include <linux/string.h>
+ #include <linux/stat.h>
+@@ -17,7 +18,9 @@
+ #include <linux/init.h>
+ #include <linux/module.h>
+ #include <linux/sysctl.h>
++#include <linux/seq_file.h>
+ #include <linux/slab.h>
++#include <linux/mount.h>
+
+ #include <asm/system.h>
+ #include <asm/uaccess.h>
+@@ -101,12 +104,19 @@ void __init proc_init_inodecache(void)
+ init_once);
+ }
+
++static int proc_show_options(struct seq_file *seq, struct dentry *root)
++{
++ return 0;
++}
++
+ static const struct super_operations proc_sops = {
+ .alloc_inode = proc_alloc_inode,
+ .destroy_inode = proc_destroy_inode,
+ .drop_inode = generic_delete_inode,
+ .evict_inode = proc_evict_inode,
+ .statfs = simple_statfs,
++ .remount_fs = proc_remount,
++ .show_options = proc_show_options,
+ };
+
+ static void __pde_users_dec(struct proc_dir_entry *pde)
+diff --git a/fs/proc/internal.h b/fs/proc/internal.h
+index 7838e5c..2925775 100644
+--- a/fs/proc/internal.h
++++ b/fs/proc/internal.h
+@@ -117,6 +117,7 @@ void pde_put(struct proc_dir_entry *pde);
+
+ int proc_fill_super(struct super_block *);
+ struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
++int proc_remount(struct super_block *sb, int *flags, char *data);
+
+ /*
+ * These are generic /proc routines that use the internal
+diff --git a/fs/proc/root.c b/fs/proc/root.c
+index 03102d9..6a8ac1d 100644
+--- a/fs/proc/root.c
++++ b/fs/proc/root.c
+@@ -18,6 +18,7 @@
+ #include <linux/bitops.h>
+ #include <linux/mount.h>
+ #include <linux/pid_namespace.h>
++#include <linux/parser.h>
+
+ #include "internal.h"
+
+@@ -36,6 +37,48 @@ static int proc_set_super(struct super_block *sb, void *data)
+ return err;
+ }
+
++enum {
++ Opt_err,
++};
++
++static const match_table_t tokens = {
++ {Opt_err, NULL},
++};
++
++static int proc_parse_options(char *options, struct pid_namespace *pid)
++{
++ char *p;
++ substring_t args[MAX_OPT_ARGS];
++
++ pr_debug("proc: options = %s\n", options);
++
++ if (!options)
++ return 1;
++
++ while ((p = strsep(&options, ",")) != NULL) {
++ int token;
++ if (!*p)
++ continue;
++
++ args[0].to = args[0].from = 0;
++ token = match_token(p, tokens, args);
++ switch (token) {
++ default:
++ pr_err("proc: unrecognized mount option \"%s\" "
++ "or missing value\n", p);
++ return 0;
++ }
++ }
++
++ return 1;
++}
++
++int proc_remount(struct super_block *sb, int *flags, char *data)
++{
++ struct pid_namespace *pid = sb->s_fs_info;
++ return !proc_parse_options(data, pid);
++}
++
+ static struct dentry *proc_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data)
+ {
+@@ -43,11 +86,15 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
+ struct super_block *sb;
+ struct pid_namespace *ns;
+ struct proc_inode *ei;
++ char *options;
+
+- if (flags & MS_KERNMOUNT)
++ if (flags & MS_KERNMOUNT) {
+ ns = (struct pid_namespace *)data;
+- else
++ options = NULL;
++ } else {
+ ns = current->nsproxy->pid_ns;
++ options = data;
++ }
+
+ sb = sget(fs_type, proc_test_super, proc_set_super, ns);
+ if (IS_ERR(sb))
+@@ -55,6 +102,10 @@ static struct dentry *proc_mount(struct file_system_type *fs_type,
+
+ if (!sb->s_root) {
+ sb->s_flags = flags;
++ if (!proc_parse_options(options, ns)) {
++ deactivate_locked_super(sb);
++ return ERR_PTR(-EINVAL);
++ }
+ err = proc_fill_super(sb);
+ if (err) {
+ deactivate_locked_super(sb);
+--
+1.7.7.5
+
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