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%3Ba=su...
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@vger.kernel.org know about it.
From foo@baz Mon Apr 9 10:16:32 CEST 2018
From: "Gustavo A. R. Silva" garsilva@embeddedor.com 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@embeddedor.com
[ 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@embeddedor.com Reviewed-by: Chanwoo Choi cw00.choi@samsung.com Signed-off-by: MyungJoo Ham myungjoo.ham@samsung.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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@embeddedor.com are
queue-4.15/pm-devfreq-fix-potential-null-pointer-dereference-in-governor_store.patch