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SubjectRe: [PATCH] slub: Potential stack overflow
Here is a patch for the second case. I think its better since it results
in an error display and it avoids the alloc for each slab. Add this piece
to your patch?

V1->V2 Fix missing kfree

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>

---
mm/slub.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c 2010-03-24 16:23:19.000000000 -0500
+++ linux-2.6/mm/slub.c 2010-03-24 16:24:21.000000000 -0500
@@ -3648,10 +3648,10 @@ static int add_location(struct loc_track
}

static void process_slab(struct loc_track *t, struct kmem_cache *s,
- struct page *page, enum track_item alloc)
+ struct page *page, enum track_item alloc,
+ unsigned long *map)
{
void *addr = page_address(page);
- DECLARE_BITMAP(map, page->objects);
void *p;

bitmap_zero(map, page->objects);
@@ -3670,8 +3670,10 @@ static int list_locations(struct kmem_ca
unsigned long i;
struct loc_track t = { 0, 0, NULL };
int node;
+ unsigned long *map = kmalloc(BITS_TO_LONGS(oo_objects(s->max)) *
+ sizeof(unsigned long), GFP_KERNEL);

- if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
+ if (!map || !alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location),
GFP_TEMPORARY))
return sprintf(buf, "Out of memory\n");

@@ -3688,11 +3690,12 @@ static int list_locations(struct kmem_ca

spin_lock_irqsave(&n->list_lock, flags);
list_for_each_entry(page, &n->partial, lru)
- process_slab(&t, s, page, alloc);
+ process_slab(&t, s, page, alloc, map);
list_for_each_entry(page, &n->full, lru)
- process_slab(&t, s, page, alloc);
+ process_slab(&t, s, page, alloc, map);
spin_unlock_irqrestore(&n->list_lock, flags);
}
+ kfree(map);

for (i = 0; i < t.count; i++) {
struct location *l = &t.loc[i];

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