[PATCH net-next] netdev: check for nla_put_u32() failures
From: Jakub Kicinski <kuba@kernel.org>
Date: 2026-08-09 00:06:11
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Make sure we check if nla_put_u32(id) was successful after creating objects. This is theoretical today, the skbs are large enough to always fit the ID. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- v2: - don't handle, just WARN v1: https://lore.kernel.org/20260609190804.1137085-2-kuba@kernel.org (local) CC: daniel@iogearbox.net CC: bobbyeshleman@gmail.com CC: joe@dama.to CC: razor@blackwall.org CC: sdf@fomichev.me CC: dw@davidwei.uk --- net/core/netdev-genl.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index c0a86f3ae33b..fa9edfdb32c2 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c@@ -1119,7 +1119,9 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) goto err_unbind; } - nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id); + /* rsp was allocated large enough */ + WARN_ON_ONCE(nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id)); + genlmsg_end(rsp, hdr); err = genlmsg_reply(rsp, info);
@@ -1253,7 +1255,9 @@ int netdev_nl_bind_tx_doit(struct sk_buff *skb, struct genl_info *info) goto err_unlock_bind_dev; } - nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id); + /* rsp was allocated large enough */ + WARN_ON_ONCE(nla_put_u32(rsp, NETDEV_A_DMABUF_ID, binding->id)); + genlmsg_end(rsp, hdr); if (bind_dev != netdev)
@@ -1420,7 +1424,9 @@ int netdev_nl_queue_create_doit(struct sk_buff *skb, struct genl_info *info) netdev_rx_queue_lease(rxq, rxq_lease); - nla_put_u32(rsp, NETDEV_A_QUEUE_ID, queue_id); + /* rsp was allocated large enough */ + WARN_ON_ONCE(nla_put_u32(rsp, NETDEV_A_QUEUE_ID, queue_id)); + genlmsg_end(rsp, hdr); netdev_unlock(dev_lease);
--
2.55.0