From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
devel@driverdev.osuosl.org, greybus-dev@lists.linaro.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Dan Carpenter <dan.carpenter@oracle.com>
Subject: [PATCH AUTOSEL 4.14 283/371] staging: greybus: light: fix a couple double frees
Date: Thu, 16 Jan 2020 12:22:35 -0500 [thread overview]
Message-ID: <20200116172403.18149-226-sashal@kernel.org> (raw)
In-Reply-To: <20200116172403.18149-1-sashal@kernel.org>
From: Dan Carpenter <dan.carpenter@oracle.com>
[ Upstream commit 329101244f214952606359d254ae883b7109e1a5 ]
The problem is in gb_lights_request_handler(). If we get a request to
change the config then we release the light with gb_lights_light_release()
and re-allocated it. However, if the allocation fails part way through
then we call gb_lights_light_release() again. This can lead to a couple
different double frees where we haven't cleared out the original values:
gb_lights_light_v4l2_unregister(light);
...
kfree(light->channels);
kfree(light->name);
I also made a small change to how we set "light->channels_count = 0;".
The original code handled this part fine and did not cause a use after
free but it was sort of complicated to read.
Fixes: 2870b52bae4c ("greybus: lights: add lights implementation")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Link: https://lore.kernel.org/r/20190829122839.GA20116@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/staging/greybus/light.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/staging/greybus/light.c b/drivers/staging/greybus/light.c
index 0f538b8c3a07..4e7575147775 100644
--- a/drivers/staging/greybus/light.c
+++ b/drivers/staging/greybus/light.c
@@ -1103,21 +1103,21 @@ static void gb_lights_channel_release(struct gb_channel *channel)
static void gb_lights_light_release(struct gb_light *light)
{
int i;
- int count;
light->ready = false;
- count = light->channels_count;
-
if (light->has_flash)
gb_lights_light_v4l2_unregister(light);
+ light->has_flash = false;
- for (i = 0; i < count; i++) {
+ for (i = 0; i < light->channels_count; i++)
gb_lights_channel_release(&light->channels[i]);
- light->channels_count--;
- }
+ light->channels_count = 0;
+
kfree(light->channels);
+ light->channels = NULL;
kfree(light->name);
+ light->name = NULL;
}
static void gb_lights_release(struct gb_lights *glights)
--
2.20.1
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prev parent reply other threads:[~2020-01-16 17:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200116172403.18149-1-sashal@kernel.org>
2020-01-16 17:19 ` [PATCH AUTOSEL 4.14 081/371] staging: most: cdev: add missing check for cdev_add failure Sasha Levin
2020-01-16 17:19 ` [PATCH AUTOSEL 4.14 104/371] staging: r8822be: check kzalloc return or bail Sasha Levin
2020-01-16 17:19 ` [PATCH AUTOSEL 4.14 115/371] staging: rtlwifi: Use proper enum for return in halmac_parse_psd_data_88xx Sasha Levin
2020-01-16 17:22 ` Sasha Levin [this message]
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