src/patches/suse-2.6.27.31/patches.apparmor/sysctl-pathname.diff

   1 From: Andreas Gruenbacher <agruen@suse.de>
   2 Subject: Factor out sysctl pathname code
   3
   4 Convert the selinux sysctl pathname computation code into a standalone
   5 function.
   6
   7 Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
   8 Signed-off-by: John Johansen <jjohansen@suse.de>
   9 Reviewed-by: James Morris <jmorris@namei.org>
  10
  11 ---
  12  include/linux/sysctl.h   |    2 ++
  13  kernel/sysctl.c          |   27 +++++++++++++++++++++++++++
  14  security/selinux/hooks.c |   34 +++++-----------------------------
  15  3 files changed, 34 insertions(+), 29 deletions(-)
  16
  17 --- a/include/linux/sysctl.h
  18 +++ b/include/linux/sysctl.h
  19 @@ -996,6 +996,8 @@ extern int proc_doulongvec_minmax(struct
  20  extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int,
  21                                       struct file *, void __user *, size_t *, loff_t *);
  22
  23 +extern char *sysctl_pathname(ctl_table *, char *, int);
  24 +
  25  extern int do_sysctl (int __user *name, int nlen,
  26                       void __user *oldval, size_t __user *oldlenp,
  27                       void __user *newval, size_t newlen);
  28 --- a/kernel/sysctl.c
  29 +++ b/kernel/sysctl.c
  30 @@ -1552,6 +1552,33 @@ void register_sysctl_root(struct ctl_tab
  31         spin_unlock(&sysctl_lock);
  32  }
  33
  34 +char *sysctl_pathname(struct ctl_table *table, char *buffer, int buflen)
  35 +{
  36 +       if (buflen < 1)
  37 +               return NULL;
  38 +       buffer += --buflen;
  39 +       *buffer = '\0';
  40 +
  41 +       while (table) {
  42 +               int namelen = strlen(table->procname);
  43 +
  44 +               if (buflen < namelen + 1)
  45 +                       return NULL;
  46 +               buflen -= namelen + 1;
  47 +               buffer -= namelen;
  48 +               memcpy(buffer, table->procname, namelen);
  49 +               *--buffer = '/';
  50 +               table = table->parent;
  51 +       }
  52 +       if (buflen < 4)
  53 +               return NULL;
  54 +       buffer -= 4;
  55 +       memcpy(buffer, "/sys", 4);
  56 +
  57 +       return buffer;
  58 +}
  59 +EXPORT_SYMBOL_GPL(sysctl_pathname);
  60 +
  61  #ifdef CONFIG_SYSCTL_SYSCALL
  62  /* Perform the actual read/write of a sysctl table entry. */
  63  static int do_sysctl_strategy(struct ctl_table_root *root,
  64 --- a/security/selinux/hooks.c
  65 +++ b/security/selinux/hooks.c
  66 @@ -1811,40 +1811,16 @@ static int selinux_capable(struct task_s
  67
  68  static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
  69  {
  70 -       int buflen, rc;
  71 -       char *buffer, *path, *end;
  72 +       char *buffer, *path;
  73 +       int rc = -ENOMEM;
  74
  75 -       rc = -ENOMEM;
  76         buffer = (char *)__get_free_page(GFP_KERNEL);
  77         if (!buffer)
  78                 goto out;
  79
  80 -       buflen = PAGE_SIZE;
  81 -       end = buffer+buflen;
  82 -       *--end = '\0';
  83 -       buflen--;
  84 -       path = end-1;
  85 -       *path = '/';
  86 -       while (table) {
  87 -               const char *name = table->procname;
  88 -               size_t namelen = strlen(name);
  89 -               buflen -= namelen + 1;
  90 -               if (buflen < 0)
  91 -                       goto out_free;
  92 -               end -= namelen;
  93 -               memcpy(end, name, namelen);
  94 -               *--end = '/';
  95 -               path = end;
  96 -               table = table->parent;
  97 -       }
  98 -       buflen -= 4;
  99 -       if (buflen < 0)
 100 -               goto out_free;
 101 -       end -= 4;
 102 -       memcpy(end, "/sys", 4);
 103 -       path = end;
 104 -       rc = security_genfs_sid("proc", path, tclass, sid);
 105 -out_free:
 106 +       path = sysctl_pathname(table, buffer, PAGE_SIZE);
 107 +       if (path)
 108 +               rc = security_genfs_sid("proc", path, tclass, sid);
 109         free_page((unsigned long)buffer);
 110  out:
 111         return rc;