ndisc: ndisc_send_redirect() must use dev_get_by_index_rcu()

ndisc: ndisc_send_redirect() must use dev_get_by_index_rcu()

[ Upstream commit 48145a57d4bbe3496e8e4880b23ea6b511e6e519 ]

ndisc_send_redirect() is called under RCU protection, not RTNL.

It must use dev_get_by_index_rcu() instead of __dev_get_by_index()

Fixes: 2f17becfbea5 ("vrf: check the original netdevice for generating redirect")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>