From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 11 Jan 2012 21:42:33 +0530 From: Ananth N Mavinakayanahalli To: Jiang Liu Cc: linux-kernel@vger.kernel.org, Anil S Keshavamurthy , "David S . Miller" , Masami Hiramatsu , Jim Keniston , Jun Ma , stable@vger.kernel.org, Jiang Liu Subject: Re: [PATCH] kprobes: fix a memory leak in function pre_handler_kretprobe() Message-ID: <20120111161233.GA13539@in.ibm.com> Reply-To: ananth@in.ibm.com References: <1326295311-10985-1-git-send-email-jiang.liu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1326295311-10985-1-git-send-email-jiang.liu@huawei.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Wed, Jan 11, 2012 at 11:21:51PM +0800, Jiang Liu wrote: > From: Jiang Liu > > In function pre_handler_kretprobe(), the allocated kretprobe_instance object > will be leaked if the entry_handler callback returns non-zero. This may cause > all the preallocated kretprobe_instance objects exhausted. This issue could be > reproduced by changing samples/kprobes/kretprobe_example.c to probe > "mutex_unlock". And the fix is straight forward, just put the allocated > kretprobe_instance object back onto the free_instances list. > > Signed-off-by: Jiang Liu > Acked-by: Jim Keniston > Acked-by: Ananth N Mavinakayanahalli Thank you Jiang. I think the correct ID for stable is now stable@vger.kernel.org. > --- > kernel/kprobes.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index e5d8464..2423295 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -1673,8 +1673,12 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p, > ri->rp = rp; > ri->task = current; > > - if (rp->entry_handler && rp->entry_handler(ri, regs)) > + if (rp->entry_handler && rp->entry_handler(ri, regs)) { > + spin_lock_irqsave(&rp->lock, flags); > + hlist_add_head(&ri->hlist, &rp->free_instances); > + spin_unlock_irqrestore(&rp->lock, flags); > return 0; > + } > > arch_prepare_kretprobe(ri, regs); > > -- > 1.7.5.4