| From 090d918623cb789ce324706b4e7525f02935966a Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 4 Oct 2018 11:44:02 -0400 |
| Subject: media: isif: fix a NULL pointer dereference bug |
| |
| From: Wenwen Wang <wang6495@umn.edu> |
| |
| [ Upstream commit a26ac6c1bed951b2066cc4b2257facd919e35c0b ] |
| |
| In isif_probe(), there is a while loop to get the ISIF base address and |
| linearization table0 and table1 address. In the loop body, the function |
| platform_get_resource() is called to get the resource. If |
| platform_get_resource() returns NULL, the loop is terminated and the |
| execution goes to 'fail_nobase_res'. Suppose the loop is terminated at the |
| first iteration because platform_get_resource() returns NULL and the |
| execution goes to 'fail_nobase_res'. Given that there is another while loop |
| at 'fail_nobase_res' and i equals to 0, one iteration of the second while |
| loop will be executed. However, the second while loop does not check the |
| return value of platform_get_resource(). This can cause a NULL pointer |
| dereference bug if the return value is a NULL pointer. |
| |
| This patch avoids the above issue by adding a check in the second while |
| loop after the call to platform_get_resource(). |
| |
| Signed-off-by: Wenwen Wang <wang6495@umn.edu> |
| Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> |
| Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/media/platform/davinci/isif.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/media/platform/davinci/isif.c b/drivers/media/platform/davinci/isif.c |
| index 99faea2e84c6b..78e37cf3470f2 100644 |
| --- a/drivers/media/platform/davinci/isif.c |
| +++ b/drivers/media/platform/davinci/isif.c |
| @@ -1106,7 +1106,8 @@ static int isif_probe(struct platform_device *pdev) |
| |
| while (i >= 0) { |
| res = platform_get_resource(pdev, IORESOURCE_MEM, i); |
| - release_mem_region(res->start, resource_size(res)); |
| + if (res) |
| + release_mem_region(res->start, resource_size(res)); |
| i--; |
| } |
| vpfe_unregister_ccdc_device(&isif_hw_dev); |
| -- |
| 2.20.1 |
| |
