[PATCH v2 bpf 1/3] libbpf: ensure umem pointer is non-NULL before dereferencing

[Ciara Loftus]

Calls to xsk_socket__create dereference the umem to access the
fill_save and comp_save pointers. Make sure the umem is non-NULL
before doing this.

Fixes: 2f6324a3937f ("libbpf: Support shared umems between queues and devices")

Acked-by: Magnus Karlsson <magnus.karls...@intel.com>
Signed-off-by: Ciara Loftus <ciara.lof...@intel.com>
---
 tools/lib/bpf/xsk.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index 526fc35c0b23..443b0cfb45e8 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -1019,6 +1019,9 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const 
char *ifname,
                       struct xsk_ring_cons *rx, struct xsk_ring_prod *tx,
                       const struct xsk_socket_config *usr_config)
 {
+       if (!umem)
+               return -EFAULT;
+
        return xsk_socket__create_shared(xsk_ptr, ifname, queue_id, umem,
                                         rx, tx, umem->fill_save,
                                         umem->comp_save, usr_config);
-- 
2.17.1