| From bfbbd2e27cb41185142edad97e4c058e75136a37 Mon Sep 17 00:00:00 2001 |
| From: Sabrina Dubroca <sd@queasysnail.net> |
| Date: Tue, 28 Aug 2018 13:40:51 +0200 |
| Subject: ipv6: fix cleanup ordering for ip6_mr failure |
| |
| [ Upstream commit afe49de44c27a89e8e9631c44b5ffadf6ace65e2 ] |
| |
| 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@queasysnail.net> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| net/ipv6/af_inet6.c | 6 +++--- |
| 1 file changed, 3 insertions(+), 3 deletions(-) |
| |
| diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c |
| index 421379014995..f7b425615c12 100644 |
| --- a/net/ipv6/af_inet6.c |
| +++ b/net/ipv6/af_inet6.c |
| @@ -1045,11 +1045,11 @@ 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); |
| -- |
| 2.17.1 |
| |