From: Eric Auger <eric.auger@xxxxxxxxxx> commit 4c80ba392bf603d468ea827d902f8e7b2505fbf4 upstream. 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: 4dbd258ff63e ("iommu: Revisit iommu_insert_resv_region() implementation") Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> Reported-by: Qian Cai <cai@xxxxxx> Reviewed-by: Jerry Snitselaar <jsnitsel@xxxxxxxxxx> Cc: Stable <stable@xxxxxxxxxxxxxxx> #v5.3+ Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/iommu/iommu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -312,8 +312,8 @@ int iommu_insert_resv_region(struct iomm 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; }