linux-kernel - [PATCH] pci: lock the pci_cfg_wait queue for the consistency of data

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20191028091809.35212-1-zhengxiang9@huawei.com>
Date:   Mon, 28 Oct 2019 17:18:09 +0800
From:   Xiang Zheng <zhengxiang9@...wei.com>
To:     <bhelgaas@...gle.com>
CC:     <zhengxiang9@...wei.com>, <wangxiongfeng2@...wei.com>,
        <wanghaibin.wang@...wei.com>, <guoheyi@...wei.com>,
        <yebiaoxiang@...wei.com>, <linux-pci@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <willy@...radead.org>,
        <rjw@...ysocki.net>, <tglx@...utronix.de>, <guohanjun@...wei.com>,
        <yangyingliang@...wei.com>
Subject: [PATCH] pci: lock the pci_cfg_wait queue for the consistency of data

Commit "7ea7e98fd8d0" suggests that the "pci_lock" is sufficient,
and all the callers of pci_wait_cfg() are wrapped with the "pci_lock".

However, since the commit "cdcb33f98244" merged, the accesses to
the pci_cfg_wait queue are not safe anymore. A "pci_lock" is
insufficient and we need to hold an additional queue lock while
read/write the wait queue.

So let's use the add_wait_queue()/remove_wait_queue() instead of
__add_wait_queue()/__remove_wait_queue().

Signed-off-by: Xiang Zheng <zhengxiang9@...wei.com>
Cc: Heyi Guo <guoheyi@...wei.com>
Cc: Biaoxiang Ye <yebiaoxiang@...wei.com>
Cc: Xiongfeng Wang <wangxiongfeng2@...wei.com>
---
 drivers/pci/access.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 2fccb5762c76..247bf36e0047 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -207,14 +207,14 @@ static noinline void pci_wait_cfg(struct pci_dev *dev)
 {
 	DECLARE_WAITQUEUE(wait, current);
 
-	__add_wait_queue(&pci_cfg_wait, &wait);
+	add_wait_queue(&pci_cfg_wait, &wait);
 	do {
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		raw_spin_unlock_irq(&pci_lock);
 		schedule();
 		raw_spin_lock_irq(&pci_lock);
 	} while (dev->block_cfg_access);
-	__remove_wait_queue(&pci_cfg_wait, &wait);
+	remove_wait_queue(&pci_cfg_wait, &wait);
 }
 
 /* Returns 0 on success, negative values indicate error. */
-- 
2.19.1