From: Ciara Loftus ciara.loftus@intel.com
commit afd0be7299533bb2e2b09104399d8a467ecbd2c5 upstream.
Wait until after the UMEM is checked for null to dereference it.
Fixes: 43f1bc1efff1 ("libbpf: Restore umem state after socket create failure") Signed-off-by: Ciara Loftus ciara.loftus@intel.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Link: https://lore.kernel.org/bpf/20210408052009.7844-1-ciara.loftus@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/lib/bpf/xsk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -777,18 +777,19 @@ int xsk_socket__create_shared(struct xsk struct xsk_ring_cons *comp, const struct xsk_socket_config *usr_config) { + bool unmap, rx_setup_done = false, tx_setup_done = false; void *rx_map = NULL, *tx_map = NULL; struct sockaddr_xdp sxdp = {}; struct xdp_mmap_offsets off; struct xsk_socket *xsk; struct xsk_ctx *ctx; int err, ifindex; - bool unmap = umem->fill_save != fill; - bool rx_setup_done = false, tx_setup_done = false;
if (!umem || !xsk_ptr || !(rx || tx)) return -EFAULT;
+ unmap = umem->fill_save != fill; + xsk = calloc(1, sizeof(*xsk)); if (!xsk) return -ENOMEM;