[PATCH bpf-next 3/4] libbpf: fix potential multiplication overflow in mmap() size calculation
From: Andrii Nakryiko <hidden>
Date: 2020-01-17 06:08:20
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [library] (libbpf), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Prevent potential overflow performed in 32-bit integers, before assigning
result to size_t. Reported by LGTM static analysis.
Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization")
Signed-off-by: Andrii Nakryiko <redacted>
---
tools/lib/bpf/libbpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3b0b88c3377d..fc41c3f2e983 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c@@ -1283,7 +1283,7 @@ static size_t bpf_map_mmap_sz(const struct bpf_map *map) long page_sz = sysconf(_SC_PAGE_SIZE); size_t map_sz; - map_sz = roundup(map->def.value_size, 8) * map->def.max_entries; + map_sz = (size_t)roundup(map->def.value_size, 8) * map->def.max_entries; map_sz = roundup(map_sz, page_sz); return map_sz; }
--
2.17.1