Avoid crashes on corrupted stack ids.
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
To: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: linux-mm@xxxxxxxxx
---
v3:
- fix the return statement
Change-Id: I0a0b38ed5057090696a2c6ff0be7cfcc24ae6738
---
lib/stackdepot.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index ed717dd08ff3..0bc6182bc7a6 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -198,9 +198,22 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle,
unsigned long **entries)
{
union handle_parts parts = { .handle = handle };
- void *slab = stack_slabs[parts.slabindex];
+ void *slab;
size_t offset = parts.offset << STACK_ALLOC_ALIGN;
- struct stack_record *stack = slab + offset;
+ struct stack_record *stack;
+
+ if (parts.slabindex > depot_index) {
+ WARN(1, "slab index %d out of bounds (%d) for stack id %08x\n",
+ parts.slabindex, depot_index, handle);
+ *entries = NULL;
+ return 0;
+ }
+ slab = stack_slabs[parts.slabindex];
+ stack = slab + offset;
+ if (!stack) {
+ entries = NULL;
+ return 0;
+ }
*entries = stack->entries;
return stack->size;
--
2.24.0.432.g9d3f5f5b63-goog
