On Tue, 25 Jul 2023 10:33:30 +0800 Lin Ma wrote: > The nla_for_each_nested parsing in function bpf_sk_storage_diag_alloc > does not check the length of the nested attribute. This can lead to an > out-of-attribute read and allow a malformed nlattr (e.g., length 0) to > be viewed as a 4 byte integer. > > This patch adds an additional check when the nlattr is getting counted. > This makes sure the latter nla_get_u32 can access the attributes with > the correct length. > > Fixes: 1ed4d92458a9 ("bpf: INET_DIAG support in bpf_sk_storage") > Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx> > Signed-off-by: Lin Ma <linma@xxxxxxxxxx> Reviewed-by: Jakub Kicinski <kuba@xxxxxxxxxx> Those who parse manually must do checks manually. It is what it is.