Commit d2e7b7d0 authored by Siddha, Suresh B's avatar Siddha, Suresh B Committed by Linus Torvalds
Browse files

[PATCH] fix potential stack overflow in mm/slab.c



On High end systems (1024 or so cpus) this can potentially cause stack
overflow. Fix the stack usage.
Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 980128f2
......@@ -3725,22 +3725,26 @@ static void do_ccupdate_local(void *info)
static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
int batchcount, int shared)
{
struct ccupdate_struct new;
struct ccupdate_struct *new;
int i;
memset(&new.new, 0, sizeof(new.new));
new = kzalloc(sizeof(*new), GFP_KERNEL);
if (!new)
return -ENOMEM;
for_each_online_cpu(i) {
new.new[i] = alloc_arraycache(cpu_to_node(i), limit,
new->new[i] = alloc_arraycache(cpu_to_node(i), limit,
batchcount);
if (!new.new[i]) {
if (!new->new[i]) {
for (i--; i >= 0; i--)
kfree(new.new[i]);
kfree(new->new[i]);
kfree(new);
return -ENOMEM;
}
}
new.cachep = cachep;
new->cachep = cachep;
on_each_cpu(do_ccupdate_local, (void *)&new, 1, 1);
on_each_cpu(do_ccupdate_local, (void *)new, 1, 1);
check_irq_on();
cachep->batchcount = batchcount;
......@@ -3748,7 +3752,7 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
cachep->shared = shared;
for_each_online_cpu(i) {
struct array_cache *ccold = new.new[i];
struct array_cache *ccold = new->new[i];
if (!ccold)
continue;
spin_lock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
......@@ -3756,7 +3760,7 @@ static int do_tune_cpucache(struct kmem_cache *cachep, int limit,
spin_unlock_irq(&cachep->nodelists[cpu_to_node(i)]->list_lock);
kfree(ccold);
}
kfree(new);
return alloc_kmemlist(cachep);
}
......@@ -4274,6 +4278,7 @@ static int leaks_show(struct seq_file *m, void *p)
show_symbol(m, n[2*i+2]);
seq_putc(m, '\n');
}
return 0;
}
......
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