bpf: Use struct_size() in kzalloc()

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows
that, in the worst scenario, could lead to heap overflows.

This code was detected with the help of Coccinelle and, audited and
fixed manually.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gustavo A. R. Silva 2021-05-13 16:50:49 -05:00 committed by David S. Miller
parent 0f3ee28033
commit fe0bdaec8d

View File

@ -524,8 +524,7 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
nr_maps++;
}
diag = kzalloc(sizeof(*diag) + sizeof(diag->maps[0]) * nr_maps,
GFP_KERNEL);
diag = kzalloc(struct_size(diag, maps, nr_maps), GFP_KERNEL);
if (!diag)
return ERR_PTR(-ENOMEM);