[PKT_SCHED]: Fix illegal memory dereferences when dumping actions
The TCA_ACT_KIND attribute is used without checking its availability when dumping actions therefore leading to a value of 0x4 being dereferenced. The use of strcmp() in tc_lookup_action_n() isn't safe when fed with string from an attribute without enforcing proper NUL termination. Both bugs can be triggered with malformed netlink message and don't require any privileges. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
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@ -776,7 +776,7 @@ static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
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return ret;
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}
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static char *
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static struct rtattr *
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find_dump_kind(struct nlmsghdr *n)
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{
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struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
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@ -804,7 +804,7 @@ find_dump_kind(struct nlmsghdr *n)
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return NULL;
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kind = tb2[TCA_ACT_KIND-1];
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return (char *) RTA_DATA(kind);
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return kind;
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}
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static int
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@ -817,16 +817,15 @@ tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
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struct tc_action a;
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int ret = 0;
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struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
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char *kind = find_dump_kind(cb->nlh);
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struct rtattr *kind = find_dump_kind(cb->nlh);
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if (kind == NULL) {
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printk("tc_dump_action: action bad kind\n");
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return 0;
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}
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a_o = tc_lookup_action_n(kind);
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a_o = tc_lookup_action(kind);
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if (a_o == NULL) {
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printk("failed to find %s\n", kind);
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return 0;
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}
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@ -834,7 +833,7 @@ tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
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a.ops = a_o;
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if (a_o->walk == NULL) {
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printk("tc_dump_action: %s !capable of dumping table\n", kind);
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printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
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goto rtattr_failure;
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}
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