Commit a03dc36b authored Aug 28, 2018 by Sabrina Dubroca Committed by David S. Miller Aug 29, 2018

ipv6: fix cleanup ordering for pingv6 registration



Commit 6d0bfe22 ("net: ipv6: Add IPv6 support to the ping socket.")
contains an error in the cleanup path of inet6_init(): when
proto_register(&pingv6_prot, 1) fails, we try to unregister
&pingv6_prot. When rawv6_init() fails, we skip unregistering
&pingv6_prot.

Example of panic (triggered by faking a failure of
 proto_register(&pingv6_prot, 1)):

    general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI
    [...]
    RIP: 0010:__list_del_entry_valid+0x79/0x160
    [...]
    Call Trace:
     proto_unregister+0xbb/0x550
     ? trace_preempt_on+0x6f0/0x6f0
     ? sock_no_shutdown+0x10/0x10
     inet6_init+0x153/0x1b8

Fixes: 6d0bfe22 ("net: ipv6: Add IPv6 support to the ping socket.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent afe49de4

net/ipv6/af_inet6.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -938,14 +938,14 @@ static int __init inet6_init(void)

		err = proto_register(&pingv6_prot, 1);
		if (err)
		goto out_unregister_ping_proto;
		goto out_unregister_raw_proto;

		/* We MUST register RAW sockets before we create the ICMP6,
		* IGMP6, or NDISC control sockets.
		*/
		err = rawv6_init();
		if (err)
		goto out_unregister_raw_proto;
		goto out_unregister_ping_proto;

		/* Register the family here so that the init calls below will
		* be able to create sockets. (?? is this dangerous ??)

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