From: Daniel Borkmann daniel@iogearbox.net
[ Upstream commit b845c898b2f1ea458d5453f0fa1da6e2dfce3bb4 ]
Currently, it is possible to create a sock hash map with key size of 0 and have the kernel return a fd back to user space. This is invalid for hash maps (and kernel also hasn't been tested for zero key size support in general at this point). Thus, reject such configuration.
Fixes: 81110384441a ("bpf: sockmap, add hash map support") Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: John Fastabend john.fastabend@gmail.com Acked-by: Song Liu songliubraving@fb.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- kernel/bpf/sockmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c index 58899601fccf..dd87d930f036 100644 --- a/kernel/bpf/sockmap.c +++ b/kernel/bpf/sockmap.c @@ -2143,7 +2143,9 @@ static struct bpf_map *sock_hash_alloc(union bpf_attr *attr) return ERR_PTR(-EPERM);
/* check sanity of attributes */ - if (attr->max_entries == 0 || attr->value_size != 4 || + if (attr->max_entries == 0 || + attr->key_size == 0 || + attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK) return ERR_PTR(-EINVAL);