Messages in this thread Patch in this message | | | From | Ricardo Ribalda Delgado <> | Subject | [PATCH v3 1/4] kernel/resource: Invalid memory access in __release_resource | Date | Wed, 22 Apr 2015 18:14:18 +0200 |
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When a resource is initialized via of_platform_populate. resource->parent is initialized to NULL via kzalloc. (of_platform_populate->of_device_alloc->of_address_to_resource)
If of_platform_depopulate is called later, resource->parent is accessed (Offset 0x30 of address 0), causing a kernel error.
This patch evaluates resouce->parent before accessing it. If it is not initialized, -EACCESS is returned.
Also a WARN is thrown, so the developer can have a hint about what needs to be fixed.
Fixes: BUG: unable to handle kernel NULL pointer deference at 0000000000000030 IP: release_resource+0x26/0x90 Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com> --- kernel/resource.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/resource.c b/kernel/resource.c index 90552aa..b7b270f 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -237,6 +237,9 @@ static int __release_resource(struct resource *old) { struct resource *tmp, **p; + if (WARN_ON(!old->parent)) + return -EINVAL; + p = &old->parent->child; for (;;) { tmp = *p; -- 2.1.4
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