This is a note to let you know that I've just added the patch titled ipv6: fix cleanup ordering for ip6_mr failure to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-fix-cleanup-ordering-for-ip6_mr-failure.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From afe49de44c27a89e8e9631c44b5ffadf6ace65e2 Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> Date: Tue, 28 Aug 2018 13:40:51 +0200 Subject: ipv6: fix cleanup ordering for ip6_mr failure From: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> commit afe49de44c27a89e8e9631c44b5ffadf6ace65e2 upstream. Commit 15e668070a64 ("ipv6: reorder icmpv6_init() and ip6_mr_init()") moved the cleanup label for ipmr_fail, but should have changed the contents of the cleanup labels as well. Now we can end up cleaning up icmpv6 even though it hasn't been initialized (jump to icmp_fail or ipmr_fail). Simply undo things in the reverse order of their initialization. Example of panic (triggered by faking a failure of icmpv6_init): kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI [...] RIP: 0010:__list_del_entry_valid+0x79/0x160 [...] Call Trace: ? lock_release+0x8a0/0x8a0 unregister_pernet_operations+0xd4/0x560 ? ops_free_list+0x480/0x480 ? down_write+0x91/0x130 ? unregister_pernet_subsys+0x15/0x30 ? down_read+0x1b0/0x1b0 ? up_read+0x110/0x110 ? kmem_cache_create_usercopy+0x1b4/0x240 unregister_pernet_subsys+0x1d/0x30 icmpv6_cleanup+0x1d/0x30 inet6_init+0x1b5/0x23f Fixes: 15e668070a64 ("ipv6: reorder icmpv6_init() and ip6_mr_init()") Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv6/af_inet6.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -1029,11 +1029,11 @@ netfilter_fail: igmp_fail: ndisc_cleanup(); ndisc_fail: - ip6_mr_cleanup(); + icmpv6_cleanup(); icmp_fail: - unregister_pernet_subsys(&inet6_net_ops); + ip6_mr_cleanup(); ipmr_fail: - icmpv6_cleanup(); + unregister_pernet_subsys(&inet6_net_ops); register_pernet_fail: sock_unregister(PF_INET6); rtnl_unregister_all(PF_INET6); Patches currently in stable-queue which might be from sd@xxxxxxxxxxxxxxx are queue-4.4/ipv6-fix-cleanup-ordering-for-ip6_mr-failure.patch