From: Andrii Nakryiko andriin@fb.com
commit 35b9211c0a2427e8f39e534f442f43804fc8d5ca upstream.
Fix bug requesting invalid size of reallocated array when constructing CO-RE relocation candidate list. This can cause problems if there are many potential candidates and a very fine-grained memory allocator bucket sizes are used.
Fixes: ddc7c3042614 ("libbpf: implement BPF CO-RE offset relocation algorithm") Reported-by: William Smith williampsmith@fb.com Signed-off-by: Andrii Nakryiko andriin@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Yonghong Song yhs@fb.com Link: https://lore.kernel.org/bpf/20200124201847.212528-1-andriin@fb.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- tools/lib/bpf/libbpf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -2744,7 +2744,9 @@ static struct ids_vec *bpf_core_find_can if (strncmp(local_name, targ_name, local_essent_len) == 0) { pr_debug("[%d] %s: found candidate [%d] %s\n", local_type_id, local_name, i, targ_name); - new_ids = realloc(cand_ids->data, cand_ids->len + 1); + new_ids = reallocarray(cand_ids->data, + cand_ids->len + 1, + sizeof(*cand_ids->data)); if (!new_ids) { err = -ENOMEM; goto err_out;