From: Alistair Popple Date: Sat, 15 May 2021 00:27:13 +0000 (-0700) Subject: kernel/resource: fix return code check in __request_free_mem_region X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=eb1f065f90cdcdcc704e9e2dc678931317c69a99;p=linux.git kernel/resource: fix return code check in __request_free_mem_region Splitting an earlier version of a patch that allowed calling __request_region() while holding the resource lock into a series of patches required changing the return code for the newly introduced __request_region_locked(). Unfortunately this change was not carried through to a subsequent commit 56fd94919b8b ("kernel/resource: fix locking in request_free_mem_region") in the series. This resulted in a use-after-free due to freeing the struct resource without properly releasing it. Fix this by correcting the return code check so that the struct is not freed if the request to add it was successful. Link: https://lkml.kernel.org/r/20210512073528.22334-1-apopple@nvidia.com Fixes: 56fd94919b8b ("kernel/resource: fix locking in request_free_mem_region") Signed-off-by: Alistair Popple Reported-by: kernel test robot Reviewed-by: David Hildenbrand Cc: Balbir Singh Cc: Dan Williams Cc: Daniel Vetter Cc: Greg Kroah-Hartman Cc: Jerome Glisse Cc: John Hubbard Cc: Muchun Song Cc: Oliver Sang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/resource.c b/kernel/resource.c index 028a5ab18818f..ca9f5198a01ff 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1805,7 +1805,7 @@ static struct resource *__request_free_mem_region(struct device *dev, REGION_DISJOINT) continue; - if (!__request_region_locked(res, &iomem_resource, addr, size, + if (__request_region_locked(res, &iomem_resource, addr, size, name, 0)) break;