From: Bui Quang Minh <minhquangbui99@xxxxxxxxx> [ 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: d5a3b1f69186 ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE") Signed-off-by: Bui Quang Minh <minhquangbui99@xxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Link: https://lore.kernel.org/bpf/20210127063653.3576-1-minhquangbui99@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/bpf/stackmap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index a2a232dec2363..2fdf6f96f9762 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -70,6 +70,8 @@ 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); if (cost >= U32_MAX - PAGE_SIZE) -- 2.27.0