From 8cf8e5a67fb07f583aac94482ba51a7930dab493 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 28 Jan 2008 20:52:12 -0800 Subject: [PATCH] [INET_DIAG]: Fix inet_diag_lock_handler error path. Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=9825 The inet_diag_lock_handler function uses ERR_PTR to encode errors but its callers were testing against NULL. This only happens when the only inet_diag modular user, DCCP, is not built into the kernel or available as a module. Also there was a problem with not dropping the mutex lock when a handler was not found, also fixed in this patch. This caused an OOPS and ss would then hang on subsequent calls, as &inet_diag_table_mutex was being left locked. Thanks to spike at ml.yaroslavl.ru for report it after trying 'ss -d' on a kernel that doesn't have DCCP available. This bug was introduced in cset d523a328fb0271e1a763e985a21f2488fd816e7e ("Fix inet_diag dead-lock regression"), after 2.6.24-rc3, so just 2.6.24 seems to be affected. Signed-off-by: Arnaldo Carvalho de Melo Acked-by: Herbert Xu Signed-off-by: David S. Miller --- net/ipv4/inet_diag.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 605ed2cd7972..4cfb15c461f1 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -259,8 +259,10 @@ static int inet_diag_get_exact(struct sk_buff *in_skb, const struct inet_diag_handler *handler; handler = inet_diag_lock_handler(nlh->nlmsg_type); - if (!handler) - return -ENOENT; + if (IS_ERR(handler)) { + err = PTR_ERR(handler); + goto unlock; + } hashinfo = handler->idiag_hashinfo; err = -EINVAL; @@ -708,8 +710,8 @@ static int inet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) struct inet_hashinfo *hashinfo; handler = inet_diag_lock_handler(cb->nlh->nlmsg_type); - if (!handler) - goto no_handler; + if (IS_ERR(handler)) + goto unlock; hashinfo = handler->idiag_hashinfo; @@ -838,7 +840,6 @@ done: cb->args[2] = num; unlock: inet_diag_unlock_handler(handler); -no_handler: return skb->len; } -- 2.30.2