From 6183f4d3a0a2ad230511987c6c362ca43ec0055f Mon Sep 17 00:00:00 2001 From: Bui Quang Minh Date: Wed, 27 Jan 2021 06:36:53 +0000 Subject: [PATCH] bpf: Check for integer overflow when using roundup_pow_of_two() 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 Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210127063653.3576-1-minhquangbui99@gmail.com --- kernel/bpf/stackmap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index aea96b638473..bfafbf115bf3 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -115,6 +115,8 @@ 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)); -- 2.34.1