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From: Stefan Nuernberger <snu@amazon.com>
To: <linux-kernel@vger.kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Juergen Gross <jgross@suse.com>,
	Ross Lagerwall <ross.lagerwall@citrix.com>,
	Uwe Dannowski <uwed@amazon.de>, Conny Seidel <consei@amazon.de>,
	Stefan Nuernberger <snu@amazon.com>,
	<xen-devel@lists.xenproject.org>, <stable@vger.kernel.org>
Subject: [PATCH] xen/pciback: Prevent NULL pointer dereference in quirks_show
Date: Fri, 6 Dec 2019 14:48:04 +0100	[thread overview]
Message-ID: <20191206134804.4537-1-snu@amazon.com> (raw)

From: Uwe Dannowski <uwed@amazon.de>

Reading /sys/bus/pci/drivers/pciback/quirks while unbinding can result
in dereferencing a NULL pointer. Instead, skip printing information
about the dangling quirk.

Reported-by: Conny Seidel <consei@amazon.de>
Signed-off-by: Uwe Dannowski <uwed@amazon.de>
Signed-off-by: Stefan Nuernberger <snu@amazon.com>

Cc: xen-devel@lists.xenproject.org
Cc: stable@vger.kernel.org
---
 drivers/xen/xen-pciback/pci_stub.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c
index 097410a7cdb7..da725e474294 100644
--- a/drivers/xen/xen-pciback/pci_stub.c
+++ b/drivers/xen/xen-pciback/pci_stub.c
@@ -1346,6 +1346,8 @@ static ssize_t quirks_show(struct device_driver *drv, char *buf)
 				   quirk->devid.subdevice);
 
 		dev_data = pci_get_drvdata(quirk->pdev);
+		if (!dev_data)
+			continue;
 
 		list_for_each_entry(cfg_entry, &dev_data->config_fields, list) {
 			field = cfg_entry->field;
-- 
2.23.0




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             reply	other threads:[~2019-12-06 13:49 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-06 13:48 Stefan Nuernberger [this message]
2019-12-06 15:11 ` [PATCH] xen/pciback: Prevent NULL pointer dereference in quirks_show Boris Ostrovsky
2019-12-06 18:09   ` Nuernberger, Stefan
2019-12-06 20:15     ` Boris Ostrovsky
2019-12-09 18:16       ` Nuernberger, Stefan
2019-12-09 21:21         ` Boris Ostrovsky

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