[PATCH net-next] ipv6: fib6_rules should return exact return value
From: Hannes Frederic Sowa <hidden>
Date: 2013-08-01 06:48:47
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
With the addition of the suppress operation
(7764a45a8f1fe74d4f7d301eaca2e558e7e2831a ("fib_rules: add .suppress
operation") we rely on accurate error reporting of the fib_rules.actions.
fib6_rule_action always returned -EAGAIN in case we could not find a
matching route and 0 if a rule was matched. This also included a match
for blackhole or prohibited rule actions which could get suppressed by
the new logic.
So adapt fib6_rule_action to always return the correct error code as
its counterpart fib4_rule_action does. This also fixes a possiblity of
nullptr-deref, where we don't match the rule, thus rt == NULL. Because
the condition rt != ip6_null_entry still holdes it seems we could later
on dereference rt->dst.
Cc: Stefan Tomanek <redacted>
Cc: Hideaki YOSHIFUJI <redacted>
Signed-off-by: Hannes Frederic Sowa <redacted>
---
net/ipv6/fib6_rules.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index e64e6a5..554a4fb 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c@@ -55,26 +55,33 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, struct fib6_table *table; struct net *net = rule->fr_net; pol_lookup_t lookup = arg->lookup_ptr; + int err = 0; switch (rule->action) { case FR_ACT_TO_TBL: break; case FR_ACT_UNREACHABLE: + err = -ENETUNREACH; rt = net->ipv6.ip6_null_entry; goto discard_pkt; default: case FR_ACT_BLACKHOLE: + err = -EINVAL; rt = net->ipv6.ip6_blk_hole_entry; goto discard_pkt; case FR_ACT_PROHIBIT: + err = -EACCES; rt = net->ipv6.ip6_prohibit_entry; goto discard_pkt; } table = fib6_get_table(net, rule->table); - if (table) - rt = lookup(net, table, flp6, flags); + if (!table) { + err = -EAGAIN; + goto out; + } + rt = lookup(net, table, flp6, flags); if (rt != net->ipv6.ip6_null_entry) { struct fib6_rule *r = (struct fib6_rule *)rule;
@@ -101,6 +108,7 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, } again: ip6_rt_put(rt); + err = -EAGAIN; rt = NULL; goto out;
@@ -108,7 +116,7 @@ discard_pkt: dst_hold(&rt->dst); out: arg->result = rt; - return rt == NULL ? -EAGAIN : 0; + return err; } static bool fib6_rule_suppress(struct fib_rule *rule, struct fib_lookup_arg *arg)
--
1.8.3.1