Commit d496aab5 authored Jan 20, 2012 by Ananth N Mavinakayanahalli Committed by Linus Torvalds Jan 23, 2012

kprobes: initialize before using a hlist



Commit ef53d9c5 ("kprobes: improve kretprobe scalability with hashed
locking") 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.

Reported by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srinivasa D S <srinivasa@in.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 2a4e64b8

kernel/kprobes.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1077,6 +1077,7 @@ void __kprobes kprobe_flush_task(struct task_struct *tk)
		/* 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 task_struct *tk)
		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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