[PATCH][RESEND] kprobes: initialize before using a hlist

From: Ananth N Mavinakayanahalli
Date: Mon Jan 09 2012 - 03:20:02 EST


From: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>

Commit ef53d9c5e introduced a bug where we can potentially leak
kretprobe_instances since we initialize a hlist head after having
used it.

Initialize the hlist head before using it.

(Resent with correct email ID for -stable)

Reported by: Jim Keniston <jkenisto@xxxxxxxxxx>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
---
kernel/kprobes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-3.2/kernel/kprobes.c
===================================================================
--- linux-3.2.orig/kernel/kprobes.c
+++ linux-3.2/kernel/kprobes.c
@@ -1077,6 +1077,7 @@ void __kprobes kprobe_flush_task(struct
/* Early boot. kretprobe_table_locks not yet initialized. */
return;

+ INIT_HLIST_HEAD(&empty_rp);
hash = hash_ptr(tk, KPROBE_HASH_BITS);
head = &kretprobe_inst_table[hash];
kretprobe_table_lock(hash, &flags);
@@ -1085,7 +1086,6 @@ void __kprobes kprobe_flush_task(struct
recycle_rp_inst(ri, &empty_rp);
}
kretprobe_table_unlock(hash, &flags);
- INIT_HLIST_HEAD(&empty_rp);
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);

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