| From | Sasha Levin <> | Subject | [PATCH AUTOSEL for 4.15 026/124] PM / devfreq: Fix potential NULL pointer dereference in governor_store | Date | Mon, 19 Mar 2018 15:47:25 +0000 |
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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> --- drivers/devfreq/devfreq.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 99c4021fc33b..fe2af6aa88fc 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -996,7 +996,8 @@ static ssize_t governor_store(struct device *dev, struct device_attribute *attr, 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; } -- 2.14.1
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