From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta0.migadu.com (out-179.mta0.migadu.com [91.218.175.179]) (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 D1FEB22424A for ; Wed, 26 Feb 2025 08:11:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740557487; cv=none; b=U04PFqYXFTOjxobOPA2myJ49fhf9/IpDR+7TJO2jLfl2cg01FmjLDuPfqEd3vg3TnFWbD9luYENEgguGwJsjYe8EwGF2TBQF2wPng7t27HovkbFwCwcrWh+PK32zHBgyZ+lIzhbOs8wnzGcpAZbaiKI6cJV2rrCyq8xLzcaJV2k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740557487; c=relaxed/simple; bh=c2nX0Z7KssjyZmmlzlpGmH9rmjGL9ARrjwnRUgnZuNg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=eN2MXmjnoEV2eN8LTtL0cyo1FVRlbj6ds8aip4p0Bd2c8hsw8yH+YZOf0NunrNZxM+EsVLNe7ae/XeOIQSgCZ5+u21Cck+OBukWnNnIt0PS997w+/6iwmv3An3+KjP8pAfCuGRAjXYC1l7Xg0tcdqqGv8bC4kU2rjBfmSgyi3IY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=NeWJjflv; arc=none smtp.client-ip=91.218.175.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="NeWJjflv" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740557484; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vQZGiPobJFLUFPmIT/bFFxZNZZw9MWEJvpreh0oySZg=; b=NeWJjflvy2xGHhypijuPIh/CTKLQ3VrMWMyyKqs1KtNdLlm1SZrB/pvt7D+STB6lpT774/ R5bZLO5oLmZoFQ2Z47swrvchDxkaMgP9AQnVzBmGqywpDfqg6hvrwMiUztjgRHQ3IAqc6/ IH3xdSga7a7WVKGctupDP+hXmiiiTqc= Date: Wed, 26 Feb 2025 09:11:21 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2] RDMA/core: fix a NULL-pointer dereference in hw_stat_device_show() To: Roman Gushchin , Jason Gunthorpe Cc: Leon Romanovsky , Maher Sanalla , Parav Pandit , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250224232048.1423635-1-roman.gushchin@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <20250224232048.1423635-1-roman.gushchin@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2025/2/25 0:20, Roman Gushchin 写道: > The following panic has been noticed in production on multiple hosts: > > [42021.807566] BUG: kernel NULL pointer dereference, address: 0000000000000028 > [42021.814463] #PF: supervisor read access in kernel mode > [42021.819549] #PF: error_code(0x0000) - not-present page > [42021.824636] PGD 0 P4D 0 > [42021.827145] Oops: 0000 [#1] SMP PTI > [42021.830598] CPU: 82 PID: 2843922 Comm: switchto-defaul Kdump: loaded Tainted: G S W I XXX > [42021.841697] Hardware name: XXX > [42021.849619] RIP: 0010:hw_stat_device_show+0x1e/0x40 [ib_core] > [42021.855362] Code: 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 49 89 d0 4c 8b 5e 20 48 8b 8f b8 04 00 00 48 81 c7 f0 fa ff ff <48> 8b 41 28 48 29 ce 48 83 c6 d0 48 c1 ee 04 69 d6 ab aa aa aa 48 > [42021.873931] RSP: 0018:ffff97fe90f03da0 EFLAGS: 00010287 > [42021.879108] RAX: ffff9406988a8c60 RBX: ffff940e1072d438 RCX: 0000000000000000 > [42021.886169] RDX: ffff94085f1aa000 RSI: ffff93c6cbbdbcb0 RDI: ffff940c7517aef0 > [42021.893230] RBP: ffff97fe90f03e70 R08: ffff94085f1aa000 R09: 0000000000000000 > [42021.900294] R10: ffff94085f1aa000 R11: ffffffffc0775680 R12: ffffffff87ca2530 > [42021.907355] R13: ffff940651602840 R14: ffff93c6cbbdbcb0 R15: ffff94085f1aa000 > [42021.914418] FS: 00007fda1a3b9700(0000) GS:ffff94453fb80000(0000) knlGS:0000000000000000 > [42021.922423] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [42021.928130] CR2: 0000000000000028 CR3: 00000042dcfb8003 CR4: 00000000003726f0 > [42021.935194] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [42021.942257] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > [42021.949324] Call Trace: > [42021.951756] > [42021.953842] [] ? show_regs+0x64/0x70 > [42021.959030] [] ? __die+0x78/0xc0 > [42021.963874] [] ? page_fault_oops+0x2b5/0x3b0 > [42021.969749] [] ? exc_page_fault+0x1a2/0x3c0 > [42021.975549] [] ? asm_exc_page_fault+0x26/0x30 > [42021.981517] [] ? __pfx_show_hw_stats+0x10/0x10 [ib_core] > [42021.988482] [] ? hw_stat_device_show+0x1e/0x40 [ib_core] > [42021.995438] [] dev_attr_show+0x1e/0x50 > [42022.000803] [] sysfs_kf_seq_show+0x81/0xe0 > [42022.006508] [] seq_read_iter+0xf4/0x410 > [42022.011954] [] vfs_read+0x16e/0x2f0 > [42022.017058] [] ksys_read+0x6e/0xe0 > [42022.022073] [] do_syscall_64+0x6a/0xa0 > [42022.027441] [] entry_SYSCALL_64_after_hwframe+0x78/0xe2 > > The problem can be reproduced using the following steps: > ip netns add foo > ip netns exec foo bash > cat /sys/class/infiniband/mlx4_0/hw_counters/* > > The problem is caused by reading hw counters from a non-initial > net namespace. In this case casting the device pointer into > an ib_device pointer using container_of() in hw_stat_device_show() is > wrong and leads to a memory corruption. Instead, rdma_device_to_ibdev() > should be used, which uses a back-reference The function rdma_device_to_ibdev uses container_of to get struct ib_core_device firstly, then gets struct ib_device via the member variable owner in struct ib_core_device. It can work well. But container_of(dev, struct ib_device, dev) is to get struct ib_device directly. Unfortunately, it caused a call trace. It seems that there is something wrong in struct ib_device. If we make further investigations, it will make us understand this problem better. Anyway, it seems good to me. Thanks, Reviewed-by: Zhu Yanjun Zhu Yanjun > (container_of(device, struct ib_core_device, dev))->owner. > > Fixes: 467f432a521a ("RDMA/core: Split port and device counter sysfs attributes") > Signed-off-by: Roman Gushchin > Cc: Jason Gunthorpe > Cc: Leon Romanovsky > Cc: Maher Sanalla > Cc: Parav Pandit > Cc: linux-rdma@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/infiniband/core/sysfs.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c > index 7491328ca5e6..0be77b8abeae 100644 > --- a/drivers/infiniband/core/sysfs.c > +++ b/drivers/infiniband/core/sysfs.c > @@ -148,7 +148,7 @@ static ssize_t hw_stat_device_show(struct device *dev, > { > struct hw_stats_device_attribute *stat_attr = > container_of(attr, struct hw_stats_device_attribute, attr); > - struct ib_device *ibdev = container_of(dev, struct ib_device, dev); > + struct ib_device *ibdev = rdma_device_to_ibdev(dev); > > return stat_attr->show(ibdev, ibdev->hw_stats_data->stats, > stat_attr - ibdev->hw_stats_data->attrs, 0, buf); > @@ -160,7 +160,7 @@ static ssize_t hw_stat_device_store(struct device *dev, > { > struct hw_stats_device_attribute *stat_attr = > container_of(attr, struct hw_stats_device_attribute, attr); > - struct ib_device *ibdev = container_of(dev, struct ib_device, dev); > + struct ib_device *ibdev = rdma_device_to_ibdev(dev); > > return stat_attr->store(ibdev, ibdev->hw_stats_data->stats, > stat_attr - ibdev->hw_stats_data->attrs, 0, buf,