recipes-kernel/linux/linux-ti33x-psp-3.2/3.2.2/0123-kprobes-initialize-before-using-a-hlist.patch

   1 From 7e71cd56cf6675bb6ffebddbc6fae6cc1bc17d4d Mon Sep 17 00:00:00 2001
   2 From: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
   3 Date: Fri, 20 Jan 2012 14:34:04 -0800
   4 Subject: [PATCH 123/130] kprobes: initialize before using a hlist
   5
   6 commit d496aab567e7e52b3e974c9192a5de6e77dce32c upstream.
   7
   8 Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed
   9 locking") introduced a bug where we can potentially leak
  10 kretprobe_instances since we initialize a hlist head after having used
  11 it.
  12
  13 Initialize the hlist head before using it.
  14
  15 Reported by: Jim Keniston <jkenisto@us.ibm.com>
  16 Acked-by: Jim Keniston <jkenisto@us.ibm.com>
  17 Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
  18 Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
  19 Cc: Srinivasa D S <srinivasa@in.ibm.com>
  20 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  21 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  22 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  23 ---
  24  kernel/kprobes.c |    2 +-
  25  1 file changed, 1 insertion(+), 1 deletion(-)
  26
  27 diff --git a/kernel/kprobes.c b/kernel/kprobes.c
  28 index e5d8464..52fd049 100644
  29 --- a/kernel/kprobes.c
  30 +++ b/kernel/kprobes.c
  31 @@ -1077,6 +1077,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
  32                 /* Early boot.  kretprobe_table_locks not yet initialized. */
  33                 return;
  34
  35 +       INIT_HLIST_HEAD(&empty_rp);
  36         hash = hash_ptr(tk, KPROBE_HASH_BITS);
  37         head = &kretprobe_inst_table[hash];
  38         kretprobe_table_lock(hash, &flags);
  39 @@ -1085,7 +1086,6 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
  40                         recycle_rp_inst(ri, &empty_rp);
  41         }
  42         kretprobe_table_unlock(hash, &flags);
  43 -       INIT_HLIST_HEAD(&empty_rp);
  44         hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
  45                 hlist_del(&ri->hlist);
  46                 kfree(ri);
  47 --
  48 1.7.9.4
  49