lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Fri, 22 Mar 2019 15:18:13 +0100
From:   Arnd Bergmann <>
To:     Jon Maloy <>,
        Ying Xue <>,
        "David S. Miller" <>
        Nick Desaulniers <>,
        Nathan Chancellor <>,
        Arnd Bergmann <>,
        Tuong Lien <>,
        LUU Duc Canh <>,
        Tung Nguyen <>,
        GhantaKrishnamurthy MohanKrishna 
Subject: [PATCH] tipc: avoid a clang -Wuninitialized warning

clang notices that we pass 'maddr' into the tipc_bearer_xmit() function
without having initialized it first:

net/tipc/node.c:831:6: error: variable 'maddr' is used uninitialized whenever 'if' condition is false
        if (!tipc_link_is_establishing(l)) {
net/tipc/node.c:847:46: note: uninitialized use occurs here
        tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
net/tipc/node.c:831:2: note: remove the 'if' if its condition is always true
        if (!tipc_link_is_establishing(l)) {
net/tipc/node.c:821:31: note: initialize the variable 'maddr' to silence this warning
        struct tipc_media_addr *maddr;
                                      = NULL

This is harmless because it won't use 'maddr' if the
queue is empty, but it's better to make that explicit
and not even call the function in that case.

As clang is able to inline the check, it then notices that
the code is safe.

Signed-off-by: Arnd Bergmann <>
 net/tipc/node.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 2dc4919ab23c..ca4cafd00a38 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -844,7 +844,8 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 	if (delete)
 		tipc_mon_remove_peer(n->net, n->addr, old_bearer_id);
-	tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
+	if (!skb_queue_empty(&xmitq))
+		tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr);
 	tipc_sk_rcv(n->net, &le->inputq);

Powered by blists - more mailing lists