aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorMuchun Song <[email protected]>2023-03-23 10:50:03 +0800
committerAndrew Morton <[email protected]>2023-03-28 15:24:32 -0700
commit1f2803b2660f4b04d48d065072c0ae0c9ca255fd (patch)
tree2c910d40709646893afef8ee0e804d86b42b2790
parent3ee2d7471fa4963a2ced0a84f0653ce88b43c5b2 (diff)
mm: kfence: fix handling discontiguous page
The struct pages could be discontiguous when the kfence pool is allocated via alloc_contig_pages() with CONFIG_SPARSEMEM and !CONFIG_SPARSEMEM_VMEMMAP. This may result in setting PG_slab and memcg_data to a arbitrary address (may be not used as a struct page), which in the worst case might corrupt the kernel. So the iteration should use nth_page(). Link: https://lkml.kernel.org/r/[email protected] Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") Signed-off-by: Muchun Song <[email protected]> Reviewed-by: Marco Elver <[email protected]> Reviewed-by: Kefeng Wang <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Jann Horn <[email protected]> Cc: SeongJae Park <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
-rw-r--r--mm/kfence/core.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index d66092dd187c..1065e0568d05 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -556,7 +556,7 @@ static unsigned long kfence_init_pool(void)
* enters __slab_free() slow-path.
*/
for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
- struct slab *slab = page_slab(&pages[i]);
+ struct slab *slab = page_slab(nth_page(pages, i));
if (!i || (i % 2))
continue;
@@ -602,7 +602,7 @@ static unsigned long kfence_init_pool(void)
reset_slab:
for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) {
- struct slab *slab = page_slab(&pages[i]);
+ struct slab *slab = page_slab(nth_page(pages, i));
if (!i || (i % 2))
continue;