This is a note to let you know that I've just added the patch titled
PM / devfreq: Fix potential NULL pointer dereference in governor_store
to the 4.15-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:
pm-devfreq-fix-potential-null-pointer-dereference-in-governor_store.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon Apr 9 10:16:32 CEST 2018
From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>
Date: Wed, 6 Dec 2017 14:20:15 -0600
Subject: PM / devfreq: Fix potential NULL pointer dereference in governor_store
From: "Gustavo A. R. Silva" <garsilva@xxxxxxxxxxxxxx>
[ Upstream commit 63f1e05f7fe9ca509c60154d6a833abf96eecdc9 ]
df->governor is being dereferenced before it is null checked,
hence there is a potential null pointer dereference.
Notice that df->governor is being null checked at line 1004:
if (df->governor) {, which implies it might be null.
Fix this by null checking df->governor before dereferencing it.
Addresses-Coverity-ID: 1401988 ("Dereference before null check")
Fixes: bcf23c79c4e4 ("PM / devfreq: Fix available_governor sysfs")
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
Signed-off-by: MyungJoo Ham <myungjoo.ham@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/devfreq/devfreq.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -996,7 +996,8 @@ static ssize_t governor_store(struct dev
if (df->governor == governor) {
ret = 0;
goto out;
- } else if (df->governor->immutable || governor->immutable) {
+ } else if ((df->governor && df->governor->immutable) ||
+ governor->immutable) {
ret = -EINVAL;
goto out;
}
Patches currently in stable-queue which might be from garsilva@xxxxxxxxxxxxxx are
queue-4.15/pm-devfreq-fix-potential-null-pointer-dereference-in-governor_store.patch