From 67ad7abf1fe888c650f9e8ed326a499e1456285c Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 15 Sep 2025 14:40:30 +0200 Subject: [PATCH] examples: genl: fix wrong attribute size This example no longer works on more recent kernels: genl-family-get error: Invalid argument dmesg says: netlink: 'genl-family-get': attribute type 1 has an invalid length. Fix this and also zero out the reserved field in the genl header, while not validated yet for dumps this could change. Upstream-Status: Backport [https://git.netfilter.org/libmnl/patch/?id=54dea548d796653534645c6e3c8577eaf7d77411] Reported-by: Divyanshu Rathore Signed-off-by: Florian Westphal (cherry picked from commit 54dea548d796653534645c6e3c8577eaf7d77411) Signed-off-by: Divyanshu Rathore --- examples/genl/genl-family-get.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/examples/genl/genl-family-get.c b/examples/genl/genl-family-get.c index ba8de12..0c20067 100644 --- a/examples/genl/genl-family-get.c +++ b/examples/genl/genl-family-get.c @@ -199,8 +199,9 @@ int main(int argc, char *argv[]) genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr)); genl->cmd = CTRL_CMD_GETFAMILY; genl->version = 1; + genl->reserved = 0; - mnl_attr_put_u32(nlh, CTRL_ATTR_FAMILY_ID, GENL_ID_CTRL); + mnl_attr_put_u16(nlh, CTRL_ATTR_FAMILY_ID, GENL_ID_CTRL); if (argc >= 2) mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, argv[1]); else -- 2.34.1