src/patches/suse-2.6.27.25/patches.fixes/reiserfs-error-buffer-locking

   1 From: Jeff Mahoney <jeffm@suse.com>
   2 Subject: [PATCH] reiserfs: add locking around error buffer
   3
   4  The formatting of the error buffer is race prone. It uses static buffers
   5  for both formatting and output. While overwriting the error buffer
   6  can product garbled output, overwriting the format buffer with incompatible
   7  % directives can cause crashes.
   8
   9 Signed-off-by: Jeff Mahoney <jeffm@suse.com>
  10 ---
  11  fs/reiserfs/prints.c |    5 ++++-
  12  1 file changed, 4 insertions(+), 1 deletion(-)
  13
  14 --- a/fs/reiserfs/prints.c
  15 +++ b/fs/reiserfs/prints.c
  16 @@ -184,7 +184,7 @@ static char *is_there_reiserfs_struct(ch
  17     printk ("bad key %lu %lu %lu %lu", key->k_dir_id, key->k_objectid,
  18             key->k_offset, key->k_uniqueness);
  19  */
  20 -
  21 +static DEFINE_SPINLOCK(error_lock);
  22  static void prepare_error_buf(const char *fmt, va_list args)
  23  {
  24         char *fmt1 = fmt_buf;
  25 @@ -192,6 +192,8 @@ static void prepare_error_buf(const char
  26         char *p = error_buf;
  27         int what;
  28
  29 +       spin_lock(&error_lock);
  30 +
  31         strcpy(fmt1, fmt);
  32
  33         while ((k = is_there_reiserfs_struct(fmt1, &what)) != NULL) {
  34 @@ -237,6 +239,7 @@ static void prepare_error_buf(const char
  35                 fmt1 = k + 2;
  36         }
  37         vsprintf(p, fmt1, args);
  38 +       spin_unlock(&error_lock);
  39
  40  }
  41