From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50064D28F for ; Tue, 31 Oct 2023 09:28:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="YBr4mz3Y" Received: from mail-wm1-x336.google.com (mail-wm1-x336.google.com [IPv6:2a00:1450:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EA5EB7; Tue, 31 Oct 2023 02:28:32 -0700 (PDT) Received: by mail-wm1-x336.google.com with SMTP id 5b1f17b1804b1-4083cd3917eso42479475e9.3; Tue, 31 Oct 2023 02:28:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1698744511; x=1699349311; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=hpuRphvrVf3Tpf7glDCxXzY38aB78+VCSilpy3ruTaY=; b=YBr4mz3YcPmGMEAEE6tat5OIzAh2b1/UbbvPf++xXgXT70PLHASArOlI+/bqp2jvai tFeevx+v2Qf0bGPTSByK4iUtRN1c2eACxQdLJoHmSUJ7goZZNjaIwmYJPyFzhASRf/gh GczK90sCmpdFLnE6Gz5fN9+aag+yVaeRqkgTNF7jdbKRBuYn8yxk+TQV5qhtwxbQc2Rp l4oFFp5QOYBJ20qb/97knE03pnH8CmwUOGVu7SYrem+d+trio1MDuP4r2mPkF8U5BgnA 00fcOBZWD305u0Bn2qWNaRnuqqGo8OlBvbg245R+LA/WyiGNFgj3CWY/QV/mSOF06qxG a4ow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698744511; x=1699349311; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=hpuRphvrVf3Tpf7glDCxXzY38aB78+VCSilpy3ruTaY=; b=ELKV/2DlQvSCjOo5XegBHJ4f8R40OKXB0DfHFu6k8R980xj4YegprzwUKaoes8Rvme AjiGFBAtrauTcyi2Xi1Ns5a2w6hcgaqi7tz+TqqWiFpK+gW/0SXpvIIoMYejEBwocmaY KTSkYcRfoApJFv02l/2GNyj7jSnXQrKaX76J85wDV4S3bvg0NqOJ20Kj/MY43TVlQw08 jUnfGoJVqbTsC+Y+QqsVvFLtBnZgetI6uT6DH4TWRfSPy0XTpmRWJ7mYPnmv9nVZ6wb9 HkDtbElqLpmO1u8brvkeD/EC7r9ab7IpFmz4AaTOlzdNAmXPgu9L75gFG6hScZS+2YPR hUfA== X-Gm-Message-State: AOJu0YwRE4vEAR7i9AqMXhdFK71dc0txv9qtci25DVUCmTxjXuEhAYiI /Lq5JPOvjI/2LrB+ntAekRI= X-Google-Smtp-Source: AGHT+IG9sjyORQpnyRpUZGDbIloDngb7K78xGL29SX64bRU+POWXPr1HNK0FPT2EiIefUXqaesYC2Q== X-Received: by 2002:a5d:690c:0:b0:32d:8da0:48d0 with SMTP id t12-20020a5d690c000000b0032d8da048d0mr8072746wru.68.1698744510694; Tue, 31 Oct 2023 02:28:30 -0700 (PDT) Received: from localhost ([81.168.73.77]) by smtp.gmail.com with ESMTPSA id c8-20020a5d63c8000000b0032f7cfac0fesm1042299wrw.51.2023.10.31.02.28.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 31 Oct 2023 02:28:30 -0700 (PDT) Date: Tue, 31 Oct 2023 09:28:30 +0000 From: Martin Habets To: Edward Adam Davis Cc: richardcochran@gmail.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, reibax@gmail.com, syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH net-next V2] ptp: fix corrupted list in ptp_open Message-ID: <20231031092830.GA20431@gmail.com> Mail-Followup-To: Edward Adam Davis , richardcochran@gmail.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, reibax@gmail.com, syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com, syzkaller-bugs@googlegroups.com References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Please use a separate mail thread for a new patch revision. See the section "Resending after review" in Documentation/process/maintainer-netdev.rst. Martin On Tue, Oct 31, 2023 at 05:07:08AM +0800, Edward Adam Davis wrote: > There is no lock protection when writing ptp->tsevqs in ptp_open(), > ptp_release(), which can cause data corruption, use mutex lock to avoid this > issue. > > Moreover, ptp_release() should not be used to release the queue in ptp_read(), > and it should be deleted together. > > Reported-and-tested-by: syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com > Fixes: 8f5de6fb2453 ("ptp: support multiple timestamp event readers") > Signed-off-by: Edward Adam Davis > --- > drivers/ptp/ptp_chardev.c | 11 +++++++++-- > drivers/ptp/ptp_clock.c | 3 +++ > drivers/ptp/ptp_private.h | 1 + > 3 files changed, 13 insertions(+), 2 deletions(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 282cd7d24077..e31551d2697d 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -109,6 +109,9 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > struct timestamp_event_queue *queue; > char debugfsname[32]; > > + if (mutex_lock_interruptible(&ptp->tsevq_mux)) > + return -ERESTARTSYS; > + > queue = kzalloc(sizeof(*queue), GFP_KERNEL); > if (!queue) > return -EINVAL; > @@ -132,15 +135,20 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > debugfs_create_u32_array("mask", 0444, queue->debugfs_instance, > &queue->dfs_bitmap); > > + mutex_unlock(&ptp->tsevq_mux); > return 0; > } > > int ptp_release(struct posix_clock_context *pccontext) > { > struct timestamp_event_queue *queue = pccontext->private_clkdata; > + struct ptp_clock *ptp = > + container_of(pccontext->clk, struct ptp_clock, clock); > unsigned long flags; > > if (queue) { > + if (mutex_lock_interruptible(&ptp->tsevq_mux)) > + return -ERESTARTSYS; > debugfs_remove(queue->debugfs_instance); > pccontext->private_clkdata = NULL; > spin_lock_irqsave(&queue->lock, flags); > @@ -148,6 +156,7 @@ int ptp_release(struct posix_clock_context *pccontext) > spin_unlock_irqrestore(&queue->lock, flags); > bitmap_free(queue->mask); > kfree(queue); > + mutex_unlock(&ptp->tsevq_mux); > } > return 0; > } > @@ -585,7 +594,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, > free_event: > kfree(event); > exit: > - if (result < 0) > - ptp_release(pccontext); > return result; > } > diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c > index 3d1b0a97301c..7930db6ec18d 100644 > --- a/drivers/ptp/ptp_clock.c > +++ b/drivers/ptp/ptp_clock.c > @@ -176,6 +176,7 @@ static void ptp_clock_release(struct device *dev) > > ptp_cleanup_pin_groups(ptp); > kfree(ptp->vclock_index); > + mutex_destroy(&ptp->tsevq_mux); > mutex_destroy(&ptp->pincfg_mux); > mutex_destroy(&ptp->n_vclocks_mux); > /* Delete first entry */ > @@ -247,6 +248,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, > if (!queue) > goto no_memory_queue; > list_add_tail(&queue->qlist, &ptp->tsevqs); > + mutex_init(&ptp->tsevq_mux); > queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL); > if (!queue->mask) > goto no_memory_bitmap; > @@ -356,6 +358,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, > if (ptp->kworker) > kthread_destroy_worker(ptp->kworker); > kworker_err: > + mutex_destroy(&ptp->tsevq_mux); > mutex_destroy(&ptp->pincfg_mux); > mutex_destroy(&ptp->n_vclocks_mux); > bitmap_free(queue->mask); > diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h > index 52f87e394aa6..1525bd2059ba 100644 > --- a/drivers/ptp/ptp_private.h > +++ b/drivers/ptp/ptp_private.h > @@ -44,6 +44,7 @@ struct ptp_clock { > struct pps_device *pps_source; > long dialed_frequency; /* remembers the frequency adjustment */ > struct list_head tsevqs; /* timestamp fifo list */ > + struct mutex tsevq_mux; /* one process at a time reading the fifo */ > struct mutex pincfg_mux; /* protect concurrent info->pin_config access */ > wait_queue_head_t tsev_wq; > int defunct; /* tells readers to go away when clock is being removed */ > -- > 2.25.1 >