Hi, > People are reporting that WireGuard experiences erratic crashes on 5.3, > and bisected it down to 7d30a7f6424e. Casually flipping through that > commit I noticed that a flag is checked using `|` instead of `&`, which in > this current case, means that a reference is never incremented, which > would result in the use-after-free users are seeing. This commit changes > the `|` to the proper `&` test.
> Cc: [email protected] > Fixes: 7d30a7f6424e ("Merge branch > 'ipv6-avoid-taking-refcnt-on-dst-during-route-lookup'") > Signed-off-by: Jason A. Donenfeld <[email protected]> Reviewed-by: Petr Vorel <[email protected]> NOTE: this change was added in d64a1f574a29 ("ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logic") Kind regards, Petr > --- > net/ipv6/ip6_fib.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c > index 87f47bc55c5e..6e2af411cd9c 100644 > --- a/net/ipv6/ip6_fib.c > +++ b/net/ipv6/ip6_fib.c > @@ -318,7 +318,7 @@ struct dst_entry *fib6_rule_lookup(struct net *net, > struct flowi6 *fl6, > if (rt->dst.error == -EAGAIN) { > ip6_rt_put_flags(rt, flags); > rt = net->ipv6.ip6_null_entry; > - if (!(flags | RT6_LOOKUP_F_DST_NOREF)) > + if (!(flags & RT6_LOOKUP_F_DST_NOREF)) > dst_hold(&rt->dst); > }
