bpf: Check for integer overflow when using roundup_pow_of_two()

[ Upstream commit 6183f4d3a0a2ad230511987c6c362ca43ec0055f ]

On 32-bit architecture, roundup_pow_of_two() can return 0 when the argument
has upper most bit set due to resulting 1UL << 32. Add a check for this case.

Fixes: d5a3b1f691 ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127063653.3576-1-minhquangbui99@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Bui Quang Minh 2021-01-27 06:36:53 +00:00 committed by Greg Kroah-Hartman
parent 52d29b4783
commit 8032bf2af9

View File

@ -116,6 +116,8 @@ static struct bpf_map *stack_map_alloc(union bpf_attr *attr)
/* hash table size must be power of 2 */
n_buckets = roundup_pow_of_two(attr->max_entries);
if (!n_buckets)
return ERR_PTR(-E2BIG);
cost = n_buckets * sizeof(struct stack_map_bucket *) + sizeof(*smap);
cost += n_buckets * (value_size + sizeof(struct stack_map_bucket));