patch "carl9170: fix debugfs crashes" added to driver-core-testing

PATCH [email protected] 1 participant 1 message Sep 21, 2016

Subsystems (2)

Stable branch CARL9170 Linux community wireless driver

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author maintainer Applied

2016-09-21 16:59 UTC #0 lore raw

This is a note to let you know that I've just added the patch titled

carl9170: fix debugfs crashes

to my driver-core git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the driver-core-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

Quoted 1 line

From 6ee6d1cb391ca85b419f8d18bdfb1f020a5e859c Mon Sep 17 00:00:00 2001

From: Christian Lamparter <[email protected]>
Date: Wed, 21 Sep 2016 18:49:36 +0200
Subject: carl9170: fix debugfs crashes

Ben Greear reported:

Quoted 7 lines

I see lots of instability as soon as I load up the carl9710 NIC. My application is going to be poking at it's debugfs files...
BUG: KASAN: slab-out-of-bounds in carl9170_debugfs_read+0xd5/0x2a0
[carl9170] at addr 0xffff8801bc1208b0
Read of size 8 by task btserver/5888
=======================================================================

Quoted 5 lines

BUG kmalloc-256 (Tainted: G W ): kasan: bad access detected
-----------------------------------------------------------------------
INFO: Allocated in seq_open+0x50/0x100 age=2690 cpu=2 pid=772
...

This breakage was caused by the introduction of intermediate fops in debugfs by commit 9fd4dcece43a
("debugfs: prevent access to possibly dead file_operations at file open")

Thankfully, the original/real fops are still available in d_fsdata.

Reported-by Ben Greear <[email protected]>

Signed-off-by Christian Lamparter <[email protected]>

Cc stable <[email protected]> # 4.7+

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/net/wireless/ath/carl9170/debug.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

drivers/net/wireless/ath/carl9170/debug.c +4 -2

index 6808db433283..ec3a64e5d2bb 100644
@@ -75,7 +75,8 @@ static ssize_t carl9170_debugfs_read(struct file *file, char __user *userbuf,
 
 	if (!ar)
 		return -ENODEV;
-	dfops = container_of(file->f_op, struct carl9170_debugfs_fops, fops);
+	dfops = container_of(debugfs_real_fops(file),
+			     struct carl9170_debugfs_fops, fops);
 
 	if (!dfops->read)
 		return -ENOSYS;

@@ -127,7 +128,8 @@ static ssize_t carl9170_debugfs_write(struct file *file,
 
 	if (!ar)
 		return -ENODEV;
-	dfops = container_of(file->f_op, struct carl9170_debugfs_fops, fops);
+	dfops = container_of(debugfs_real_fops(file),
+			     struct carl9170_debugfs_fops, fops);
 
 	if (!dfops->write)
 		return -ENOSYS;

Signature · 1 line

2.10.0