diff options
| author | Xin Long <lucien.xin@gmail.com> | 2019-03-20 14:45:48 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-04-03 06:27:23 +0200 |
| commit | 282c70c23454fd62d4571a1a6f6482900b3e5ee4 (patch) | |
| tree | 237d3033c82fa0b01c80b2d39d1f695e54d5532f /net/ipv6/route.c | |
| parent | 8122233e877a4d4632885e466f00144fea54acb3 (diff) | |
ipv6: make ip6_create_rt_rcu return ip6_null_entry instead of NULL
[ Upstream commit 1c87e79a002f6a159396138cd3f3ab554a2a8887 ]
Jianlin reported a crash:
[ 381.484332] BUG: unable to handle kernel NULL pointer dereference at 0000000000000068
[ 381.619802] RIP: 0010:fib6_rule_lookup+0xa3/0x160
[ 382.009615] Call Trace:
[ 382.020762] <IRQ>
[ 382.030174] ip6_route_redirect.isra.52+0xc9/0xf0
[ 382.050984] ip6_redirect+0xb6/0xf0
[ 382.066731] icmpv6_notify+0xca/0x190
[ 382.083185] ndisc_redirect_rcv+0x10f/0x160
[ 382.102569] ndisc_rcv+0xfb/0x100
[ 382.117725] icmpv6_rcv+0x3f2/0x520
[ 382.133637] ip6_input_finish+0xbf/0x460
[ 382.151634] ip6_input+0x3b/0xb0
[ 382.166097] ipv6_rcv+0x378/0x4e0
It was caused by the lookup function __ip6_route_redirect() returns NULL in
fib6_rule_lookup() when ip6_create_rt_rcu() returns NULL.
So we fix it by simply making ip6_create_rt_rcu() return ip6_null_entry
instead of NULL.
v1->v2:
- move down 'fallback:' to make it more readable.
Fixes: e873e4b9cc7e ("ipv6: use fib6_info_hold_safe() when necessary")
Reported-by: Jianlin Shi <jishi@redhat.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Acked-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv6/route.c')
| -rw-r--r-- | net/ipv6/route.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 8dad1d690b78..0086acc16f3c 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1040,14 +1040,20 @@ static struct rt6_info *ip6_create_rt_rcu(struct fib6_info *rt) struct rt6_info *nrt; if (!fib6_info_hold_safe(rt)) - return NULL; + goto fallback; nrt = ip6_dst_alloc(dev_net(dev), dev, flags); - if (nrt) - ip6_rt_copy_init(nrt, rt); - else + if (!nrt) { fib6_info_release(rt); + goto fallback; + } + ip6_rt_copy_init(nrt, rt); + return nrt; + +fallback: + nrt = dev_net(dev)->ipv6.ip6_null_entry; + dst_hold(&nrt->dst); return nrt; } @@ -1096,10 +1102,6 @@ restart: dst_hold(&rt->dst); } else { rt = ip6_create_rt_rcu(f6i); - if (!rt) { - rt = net->ipv6.ip6_null_entry; - dst_hold(&rt->dst); - } } rcu_read_unlock(); |