From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout01.posteo.de (mout01.posteo.de [185.67.36.65]) (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 4DCE3801 for ; Mon, 18 Apr 2022 12:23:08 +0000 (UTC) Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id A5BC424002C for ; Mon, 18 Apr 2022 14:17:22 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1650284242; bh=m06zaNElDOLmrPptGcaA5mPzK3FeCBh7vUpbw9C7Aao=; h=From:To:Cc:Subject:Date:From; b=oj8Sw8oP3Ux5jhs3XDkDp8GFL5aVKVx7HFlEMHhBH55I+8CllrlJEJNiifohEQZjn j4StBp6Z+VAxqmOa5LpdWHeRl4nvfHcI8eioFDbtCJu/rt9IjPOXoSj8G58Sn3I6pZ 01PWym0i4o+KokdfAwf3iCjELBpljtDcjYEI0x10BbEweYv+LSwWxE10rN6HPsHhIE TfmG5ObrWy4HbVCrdw/M+sDIUeYRAPg5FKFmZKN1VuxwF6Z54lLk9b3KEwk+CrYpf8 p5O95hZ8C6pTHt7IRko0FihmlGEIufIJ/yppCK4gmdJnpcsuryxdujKvtUQixJcQFC r6qLIuzcUU25A== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4KhmC30fQpz6trV; Mon, 18 Apr 2022 14:17:03 +0200 (CEST) From: Manuel Ullmann To: Igor Russkikh Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, regressions@lists.linux.dev Subject: [PATCH] net: atlantic: invert deep par in pm functions, preventing null derefs Date: Mon, 18 Apr 2022 12:17:02 +0000 Message-ID: <87sfqaa8n5.fsf@posteo.de> Precedence: bulk X-Mailing-List: regressions@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain From: Manuel Ullmann >From 6c4cd8210835489da84bf4ee5049945dc0f2c986 Mon Sep 17 00:00:00 2001 Date: Mon, 18 Apr 2022 00:20:01 +0200 This will reset deeply on freeze and thaw instead of suspend and resume and prevent null pointer dereferences of the uninitialized ring 0 buffer while thawing. The impact is an indefinitely hanging kernel. You can't switch consoles after this and the only possible user interaction is SysRq. BUG: kernel NULL pointer dereference RIP: 0010:aq_ring_rx_fill+0xcf/0x210 [atlantic] aq_vec_init+0x85/0xe0 [atlantic] aq_nic_init+0xf7/0x1d0 [atlantic] atl_resume_common+0x4f/0x100 [atlantic] pci_pm_thaw+0x42/0xa0 resolves in aq_ring.o to ``` 0000000000000ae0 : { /* ... */ baf: 48 8b 43 08 mov 0x8(%rbx),%rax buff->flags = 0U; /* buff is NULL */ ``` The bug has been present since the introduction of the new pm code in 8aaa112a57c1 ("net: atlantic: refactoring pm logic") and was hidden until 8ce84271697a ("net: atlantic: changes for multi-TC support"), which refactored the aq_vec_{free,alloc} functions into aq_vec_{,ring}_{free,alloc}, but is technically not wrong. The original functions just always reinitialized the buffers on S3/S4. If the interface is down before freezing, the bug does not occur. It does not matter, whether the initrd contains and loads the module before thawing. So the fix is to invert the boolean parameter deep in all pm function calls, which was clearly intended to be set like that. First report was on Github [1], which you have to guess from the resume logs in the posted dmesg snippet. Recently I posted one on Bugzilla [2], since I did not have an AQC device so far. #regzbot introduced: 8ce84271697a #regzbot from: koo5 #regzbot monitor: https://github.com/Aquantia/AQtion/issues/32 Fixes: 8aaa112a57c1 ("net: atlantic: refactoring pm logic") Link: https://github.com/Aquantia/AQtion/issues/32 [1] Link: https://bugzilla.kernel.org/show_bug.cgi?id=215798 [2] Cc: stable@vger.kernel.org Reported-by: koo5 Signed-off-by: Manuel Ullmann --- Once in mainline, this should be backported to 5.10 and newer supported stable branches. Although 5.4 includes the bug, it is not affected (see above). As a side effect, this might increase suspend/resume performance, although I did no measurements. drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c b/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c index 797a95142d1f..3a529ee8c834 100644 --- a/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c +++ b/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c @@ -444,22 +444,22 @@ static int atl_resume_common(struct device *dev, bool deep) static int aq_pm_freeze(struct device *dev) { - return aq_suspend_common(dev, false); + return aq_suspend_common(dev, true); } static int aq_pm_suspend_poweroff(struct device *dev) { - return aq_suspend_common(dev, true); + return aq_suspend_common(dev, false); } static int aq_pm_thaw(struct device *dev) { - return atl_resume_common(dev, false); + return atl_resume_common(dev, true); } static int aq_pm_resume_restore(struct device *dev) { - return atl_resume_common(dev, true); + return atl_resume_common(dev, false); } static const struct dev_pm_ops aq_pm_ops = { base-commit: ce522ba9ef7e2d9fb22a39eb3371c0c64e2a433e -- 2.35.1