From afd0be7299533bb2e2b09104399d8a467ecbd2c5 Mon Sep 17 00:00:00 2001 From: Ciara Loftus Date: Thu, 8 Apr 2021 05:20:09 +0000 Subject: [PATCH] libbpf: Fix potential NULL pointer dereference 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 Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20210408052009.7844-1-ciara.loftus@intel.com --- tools/lib/bpf/xsk.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index d24b5cc..007fe5d 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -852,18 +852,19 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr, 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; -- 2.7.4