Commit 4c80ba39 authored Nov 26, 2019 by Eric Auger Committed by Linus Torvalds Dec 16, 2019

iommu: fix KASAN use-after-free in iommu_insert_resv_region



In case the new region gets merged into another one, the nr list node is
freed.  Checking its type while completing the merge algorithm leads to
a use-after-free.  Use new->type instead.

Fixes: 4dbd258f ("iommu: Revisit iommu_insert_resv_region() implementation")
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reported-by: Qian Cai <cai@lca.pw>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Stable <stable@vger.kernel.org> #v5.3+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7de7de7c

drivers/iommu/iommu.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -312,8 +312,8 @@ int iommu_insert_resv_region(struct iommu_resv_region *new,
		list_for_each_entry_safe(iter, tmp, regions, list) {
		phys_addr_t top_end, iter_end = iter->start + iter->length - 1;

		/* no merge needed on elements of different types than @nr */
		if (iter->type != nr->type) {
		/* no merge needed on elements of different types than @new */
		if (iter->type != new->type) {
		list_move_tail(&iter->list, &stack);
		continue;
		}

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