From 9ba74e6c9e9d0c5c1e5792a7111fc7d1a0589cb8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 9 Dec 2021 23:44:21 -0800 Subject: net: add networking namespace refcount tracker We have 100+ syzbot reports about netns being dismantled too soon, still unresolved as of today. We think a missing get_net() or an extra put_net() is the root cause. In order to find the bug(s), and be able to spot future ones, this patch adds CONFIG_NET_NS_REFCNT_TRACKER and new helpers to precisely pair all put_net() with corresponding get_net(). To use these helpers, each data structure owning a refcount should also use a "netns_tracker" to pair the get and put. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski --- net/Kconfig.debug | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/Kconfig.debug') diff --git a/net/Kconfig.debug b/net/Kconfig.debug index fb5c70e01cb3..2f50611df858 100644 --- a/net/Kconfig.debug +++ b/net/Kconfig.debug @@ -8,3 +8,12 @@ config NET_DEV_REFCNT_TRACKER help Enable debugging feature to track device references. This adds memory and cpu costs. + +config NET_NS_REFCNT_TRACKER + bool "Enable networking namespace refcount tracking" + depends on DEBUG_KERNEL && STACKTRACE_SUPPORT + select REF_TRACKER + default n + help + Enable debugging feature to track netns references. + This adds memory and cpu costs. -- cgit