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From: Sam Bradshaw <sbradshaw@micron.com>
To: <axboe@kernel.dk>
Cc: <linux-kernel@vger.kernel.org>, <asamymuthupa@micron.com>,
	<sbradshaw@micron.com>
Subject: [PATCH][TRIVIAL] mtip32xx: Fix NULL pointer dereference during module unload
Date: Tue, 14 May 2013 14:52:09 -0700	[thread overview]
Message-ID: <5192B209.1010301@micron.com> (raw)

An open file-handle to one or more of the driver exported debugfs
nodes causes raciness in recursive removal during module unload;
sometimes a stale parent dentry is dereferenced when more than 1
pci device is present.

Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
---
diff --git a/drivers/block/mtip32xx/mtip32xx.c
b/drivers/block/mtip32xx/mtip32xx.c
index 847107e..e366c74 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -3002,7 +3002,8 @@ static int mtip_hw_debugfs_init(struct driver_data
*dd)

 static void mtip_hw_debugfs_exit(struct driver_data *dd)
 {
-	debugfs_remove_recursive(dd->dfs_node);
+	if (dd->dfs_node)
+		debugfs_remove_recursive(dd->dfs_node);
 }




             reply	other threads:[~2013-05-14 21:50 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-14 21:52 Sam Bradshaw [this message]
2013-05-15  8:04 ` [PATCH][TRIVIAL] mtip32xx: Fix NULL pointer dereference during module unload Jens Axboe
  -- strict thread matches above, loose matches on Subject: below --
2013-05-14 21:29 Sam Bradshaw

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