This is a note to let you know that I've just added the patch titled net: appletalk: cops: Fix data race in cops_probe1 to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-appletalk-cops-fix-data-race-in-cops_probe1.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 4ec4046c6ddb6bec1ee6aa49d7ce6cc47cd760f6 Author: Saubhik Mukherjee <saubhik.mukherjee@xxxxxxxxx> Date: Mon May 24 19:07:12 2021 +0530 net: appletalk: cops: Fix data race in cops_probe1 [ Upstream commit a4dd4fc6105e54393d637450a11d4cddb5fabc4f ] In cops_probe1(), there is a write to dev->base_addr after requesting an interrupt line and registering the interrupt handler cops_interrupt(). The handler might be called in parallel to handle an interrupt. cops_interrupt() tries to read dev->base_addr leading to a potential data race. So write to dev->base_addr before calling request_irq(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Saubhik Mukherjee <saubhik.mukherjee@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/appletalk/cops.c b/drivers/net/appletalk/cops.c index 1b2e9217ec78..d520ce32ddbf 100644 --- a/drivers/net/appletalk/cops.c +++ b/drivers/net/appletalk/cops.c @@ -324,6 +324,8 @@ static int __init cops_probe1(struct net_device *dev, int ioaddr) break; } + dev->base_addr = ioaddr; + /* Reserve any actual interrupt. */ if (dev->irq) { retval = request_irq(dev->irq, cops_interrupt, 0, dev->name, dev); @@ -331,8 +333,6 @@ static int __init cops_probe1(struct net_device *dev, int ioaddr) goto err_out; } - dev->base_addr = ioaddr; - lp = netdev_priv(dev); spin_lock_init(&lp->lock);