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 4.4-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-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fcd06e1e4e7a17fe6429c7696028f36a78e52453
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 7f2a032c354c..841a5de58c7c 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);
