This is a note to let you know that I've just added the patch titled
cxl: Check if afu is not null in cxl_slbia
to the 4.1-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:
cxl-check-if-afu-is-not-null-in-cxl_slbia.patch
and it can be found in the queue-4.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2c069a118fe1d80c47dca84e1561045fc7f3cc9e Mon Sep 17 00:00:00 2001
From: Daniel Axtens <dja@xxxxxxxxxx>
Date: Fri, 10 Jul 2015 09:04:25 +1000
Subject: cxl: Check if afu is not null in cxl_slbia
From: Daniel Axtens <dja@xxxxxxxxxx>
commit 2c069a118fe1d80c47dca84e1561045fc7f3cc9e upstream.
The pointer to an AFU in the adapter's list of AFUs can be null
if we're in the process of removing AFUs. The afu_list_lock
doesn't guard against this.
Say we have 2 slices, and we're in the process of removing cxl.
- We remove the AFUs in order (see cxl_remove). In cxl_remove_afu
for AFU 0, we take the lock, set adapter->afu[0] = NULL, and
release the lock.
- Then we get an slbia. In cxl_slbia we take the lock, and set
afu = adapter->afu[0], which is NULL.
- Therefore our attempt to check afu->enabled will blow up.
Therefore, check if afu is a null pointer before dereferencing it.
Signed-off-by: Daniel Axtens <dja@xxxxxxxxxx>
Acked-by: Michael Neuling <mikey@xxxxxxxxxxx>
Acked-by: Ian Munsie <imunsie@xxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/cxl/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/misc/cxl/main.c
+++ b/drivers/misc/cxl/main.c
@@ -73,7 +73,7 @@ static inline void cxl_slbia_core(struct
spin_lock(&adapter->afu_list_lock);
for (slice = 0; slice < adapter->slices; slice++) {
afu = adapter->afu[slice];
- if (!afu->enabled)
+ if (!afu || !afu->enabled)
continue;
rcu_read_lock();
idr_for_each_entry(&afu->contexts_idr, ctx, id)
Patches currently in stable-queue which might be from dja@xxxxxxxxxx are
queue-4.1/cxl-check-if-afu-is-not-null-in-cxl_slbia.patch
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