[PATCH rdma-next v3 3/5] IB/core: Fix IPv6 netlink message size in ib_nl_ip_send_msg()

Edward Srouji
2026-04-27T11:03:28Z

From: Maher Sanalla <msanalla@nvidia.com>

When resolving an RDMA-CM IPv6 address, ib_nl_ip_send_msg() sends a
netlink request to the userspace daemon to perform IP-to-GID
resolution in certain cases. The function allocates the netlink message
buffer using nla_total_size(sizeof(size)), which passes 8 bytes (the
size of size_t) instead of 16 bytes (the size of an IPv6 address).
This results in an 8-byte under-allocation.

This is currently masked by nlmsg_new() over-allocation of the skb
in its internal logic. However, the code remains incorrect.

Fix the issue by supplying the proper IPv6 address length to
nla_total_size().

Fixes: ae43f8286730 ("IB/core: Add IP to GID netlink offload")
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Patrisious Haddad <phaddad@nvidia.com>
Signed-off-by: Edward Srouji <edwards@nvidia.com>
---
drivers/infiniband/core/addr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/addr.c b/drivers/infiniband/core/addr.c
index 6526fda8f9c0bbbcddcf54f5c953d3f7a9785d66..5cd930d47eae52d35db8657ab3fc5993c5cd7770 100644
--- a/drivers/infiniband/core/addr.c
+++ b/drivers/infiniband/core/addr.c
@@ -150,7 +150,7 @@ static int ib_nl_ip_send_msg(struct rdma_dev_addr *dev_addr,
attrtype = RDMA_NLA_F_MANDATORY | LS_NLA_TYPE_IPV6;
}

- len = nla_total_size(sizeof(size));
+ len = nla_total_size(size);
len += NLMSG_ALIGN(sizeof(*header));

skb = nlmsg_new(len, GFP_KERNEL);

--
2.49.0