Commit 6183f4d3 authored by Bui Quang Minh's avatar Bui Quang Minh Committed by Daniel Borkmann
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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: d5a3b1f6 ("bpf: introduce BPF_MAP_TYPE_STACK_TRACE")
Signed-off-by: default avatarBui Quang Minh <minhquangbui99@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210127063653.3576-1-minhquangbui99@gmail.com
parent 548f1191

kernel/bpf/stackmap.c

+2 −0
Original line number Diff line number Diff line
@@ -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));