From b87b6194be631c94785fe93398651e804ed43e28 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 21 Feb 2018 04:41:59 +0100 Subject: [PATCH] netlink: put module reference if dump start fails Before, if cb->start() failed, the module reference would never be put, because cb->cb_running is intentionally false at this point. Users are generally annoyed by this because they can no longer unload modules that leak references. Also, it may be possible to tediously wrap a reference counter back to zero, especially since module.c still uses atomic_inc instead of refcount_inc. This patch expands the error path to simply call module_put if cb->start() fails. Fixes: 41c87425a1ac ("netlink: do not set cb_running if dump's start() errs") Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 2ad445c1d27c..07e8478068f0 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2308,7 +2308,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, if (cb->start) { ret = cb->start(cb); if (ret) - goto error_unlock; + goto error_put; } nlk->cb_running = true; @@ -2328,6 +2328,8 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, */ return -EINTR; +error_put: + module_put(control->module); error_unlock: sock_put(sk); mutex_unlock(nlk->cb_mutex); -- 2.30.2