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 21C004423 for ; Sun, 5 Nov 2023 13:36:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="SKtCfxko" Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8432CA; Sun, 5 Nov 2023 05:36:44 -0800 (PST) Received: by mail-pj1-x1032.google.com with SMTP id 98e67ed59e1d1-27fe16e8e02so572477a91.0; Sun, 05 Nov 2023 05:36:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699191404; x=1699796204; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=E2jAj5sYDtWpP4saEAb+BaMouDW7PQzuo3xBxPi2ywM=; b=SKtCfxkomgiPbnnCE2Y6Z+i1xnCA3qD3QQOcP6gNviedC7FHzv0NgOlriHrKMCgHuq LwxymtMss+iWajmC7ZXXJOAC9/oSw10pkCD9PCb6FGlobzbVcORGOz+M7QLapFzYltP3 HJYl8BpoQbyYUOi3CTpOEwGUZMFAzcLzG7azeDAuU7ny0Kbr5tpWTWOU5KMqfRGM1+yZ FEDR13WEzLC0jeJHy7Q+G3hzY5zHUm6DJdUK+/Hb5bGo8+GSZcBA7sa+kWBUhLdDRhMx LLmzD/EAtCT2BODGDG7HCDm1dpbzy52PG+1JbHuBXx3ClHNt607JN8qljg2ExuyuM0q5 38TQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699191404; x=1699796204; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=E2jAj5sYDtWpP4saEAb+BaMouDW7PQzuo3xBxPi2ywM=; b=XWOEMx3k2zgnYGXzCq14hy9LiuzHntV6UvVp6w03OXZCr5JnoWLcPZNu7vMqfv6kyd OYKiwDFF1ebdOQ2UiVB5TyDJ7TP/hgJ78mxjY83R+KM++X4t+iYxvhrg+svxhz0hMzqB h21TcVSd7uFulnTReBSMTyQhUS7KIWhNhexr5Su7UuZrZ6CfHhm8qtQxoqmF8f7qNXxD HsMY74OpIhnyuSTIaJWuNBlwcfzaBB87CBpxidAnUXGBkz9hdlN6jKOQaJVSblZQ0gEE 4HwLiswjQNm50NyPOZ+jrMh+3jfkMxtyuM+rYm9RY+z5biUTfNACDfrmT8+ksdNpsM2v lGWg== X-Gm-Message-State: AOJu0YxWep+gGwQgzCnpTH0MzNjBEAavOcGbwI7UUGY2Bkbs2dDj6rii +3UUpzqF2oRL4meqT+Z81W5VRF6K3aE= X-Google-Smtp-Source: AGHT+IEmf3anqwkh9FIocMU4NjQRNG8f2nfgZa+KPOs9EQlI7fo5I9ZWuEdSyH89jgVXHNEUmjLnTA== X-Received: by 2002:a17:902:f214:b0:1cc:27fa:1fb7 with SMTP id m20-20020a170902f21400b001cc27fa1fb7mr23843729plc.5.1699191404181; Sun, 05 Nov 2023 05:36:44 -0800 (PST) Received: from hoboy.vegasvil.org ([2601:640:8000:54:e2d5:5eff:fea5:802f]) by smtp.gmail.com with ESMTPSA id jw24-20020a170903279800b001c9cb2fb8d8sm4234025plb.49.2023.11.05.05.36.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 05 Nov 2023 05:36:43 -0800 (PST) Date: Sun, 5 Nov 2023 05:36:41 -0800 From: Richard Cochran To: Edward Adam Davis Cc: davem@davemloft.net, habetsm.xilinx@gmail.com, jeremy@jcline.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, reibax@gmail.com, syzbot+df3f3ef31f60781fa911@syzkaller.appspotmail.com Subject: Re: [PATCH net-next V6] ptp: fix corrupted list in ptp_open Message-ID: 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: Edward! On Sun, Nov 05, 2023 at 10:12:08AM +0800, Edward Adam Davis wrote: > There is no lock protection when writing ptp->tsevqs in ptp_open() and > ptp_release(), which can cause data corruption, use spin 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. Change to: "it should be deleted altogether" > 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 | 1 + > drivers/ptp/ptp_private.h | 1 + > 3 files changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c > index 282cd7d24077..31594f40a21e 100644 > --- a/drivers/ptp/ptp_chardev.c > +++ b/drivers/ptp/ptp_chardev.c > @@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > container_of(pccontext->clk, struct ptp_clock, clock); > struct timestamp_event_queue *queue; > char debugfsname[32]; > + unsigned long flags; > > queue = kzalloc(sizeof(*queue), GFP_KERNEL); > if (!queue) > @@ -119,8 +120,10 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode) > } > bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS); > spin_lock_init(&queue->lock); > + spin_lock_irqsave(&ptp->tsevqs_lock, flags); > list_add_tail(&queue->qlist, &ptp->tsevqs); > pccontext->private_clkdata = queue; Move this assignment outside of locked region, i.e. after spin_unlock_irqrestore(). > + spin_unlock_irqrestore(&ptp->tsevqs_lock, flags); > > /* Debugfs contents */ > sprintf(debugfsname, "0x%p", queue); > @@ -139,13 +142,15 @@ int ptp_release(struct posix_clock_context *pccontext) > { > struct timestamp_event_queue *queue = pccontext->private_clkdata; > unsigned long flags; > + struct ptp_clock *ptp = > + container_of(pccontext->clk, struct ptp_clock, clock); > > if (queue) { Please remove this test. Since you removed ptp_release() from ptp_read(), the queue cannot be NULL. > debugfs_remove(queue->debugfs_instance); > + spin_lock_irqsave(&ptp->tsevqs_lock, flags); > pccontext->private_clkdata = NULL; Move this assignment outside of locked region. > - spin_lock_irqsave(&queue->lock, flags); > list_del(&queue->qlist); > - spin_unlock_irqrestore(&queue->lock, flags); > + spin_unlock_irqrestore(&ptp->tsevqs_lock, flags); > bitmap_free(queue->mask); > kfree(queue); > } > @@ -585,7 +590,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags, > free_event: > kfree(event); > exit: > - if (result < 0) > - ptp_release(pccontext); This is good, but please put it into a separate patch, along with the removal of the bogus "if (queue)" test in ptp_release(). > return result; > } > diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c > index 3d1b0a97301c..ea82648ad557 100644 > --- a/drivers/ptp/ptp_clock.c > +++ b/drivers/ptp/ptp_clock.c > @@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, > if (!queue) > goto no_memory_queue; > list_add_tail(&queue->qlist, &ptp->tsevqs); > + spin_lock_init(&ptp->tsevqs_lock); > queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL); > if (!queue->mask) > goto no_memory_bitmap; > diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h > index 52f87e394aa6..63af246f17eb 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 */ > + spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/ Please change this comment to "protects tsevqs from concurrent access" > 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 > Since v6.6 now contains the original commit, please change subject to [net]. Thanks, Richard