UPSTREAM: iommu/iova: Fix alloc iova overflows issue
In __alloc_and_insert_iova_range, there is an issue that retry_pfn
overflows. The value of iovad->anchor.pfn_hi is ~0UL, then when
iovad->cached_node is iovad->anchor, curr_iova->pfn_hi + 1 will
overflow. As a result, if the retry logic is executed, low_pfn is
updated to 0, and then new_pfn < low_pfn returns false to make the
allocation successful.
This issue occurs in the following two situations:
1. The first iova size exceeds the domain size. When initializing
iova domain, iovad->cached_node is assigned as iovad->anchor. For
example, the iova domain size is 10M, start_pfn is 0x1_F000_0000,
and the iova size allocated for the first time is 11M. The
following is the log information, new->pfn_lo is smaller than
iovad->cached_node.
Example log as follows:
[ 223.798112][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range
start_pfn:0x1f0000,retry_pfn:0x0,size:0xb00,limit_pfn:0x1f0a00
[ 223.799590][T1705487] sh: [name:iova&]__alloc_and_insert_iova_range
success start_pfn:0x1f0000,new->pfn_lo:0x1efe00,new->pfn_hi:0x1f08ff
2. The node with the largest iova->pfn_lo value in the iova domain
is deleted, iovad->cached_node will be updated to iovad->anchor,
and then the alloc iova size exceeds the maximum iova size that can
be allocated in the domain.
After judging that retry_pfn is less than limit_pfn, call retry_pfn+1
to fix the overflow issue.
Signed-off-by: jianjiao zeng <jianjiao.zeng@mediatek.com>
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
Cc: <stable@vger.kernel.org> # 5.15.*
Fixes: 4e89dce72521 ("iommu/iova: Retry from last rb tree node if iova search fails")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20230111063801.25107-1-yf.wang@mediatek.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Bug: 265596669
Bug: 269205130
(cherry picked from commit dcdb3ba7e2a8caae7bfefd603bc22fd0ce9a389c)
Change-Id: I810ad7023267c7c276961eefbceb652439799c30
[Yunfei: Resolved minor conflict for variable low_pfn_new]
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>
(cherry picked from commit f069ba2b3db07a07491299ebbd19ee33475d5609)
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 5399494..95c9f79 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -218,7 +218,7 @@
curr = __get_cached_rbnode(iovad, limit_pfn);
curr_iova = rb_entry(curr, struct iova, node);
- low_pfn_new = curr_iova->pfn_hi + 1;
+ low_pfn_new = curr_iova->pfn_hi;
retry:
do {
@@ -232,7 +232,7 @@
if (high_pfn < size || new_pfn < low_pfn) {
if (low_pfn == iovad->start_pfn && low_pfn_new < limit_pfn) {
high_pfn = limit_pfn;
- low_pfn = low_pfn_new;
+ low_pfn = low_pfn_new + 1;
curr = &iovad->anchor.node;
curr_iova = rb_entry(curr, struct iova, node);
goto retry;
