diff options
author | WANG Cong <xiyou.wangcong@gmail.com> | 2017-05-04 14:54:17 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2017-05-08 14:35:03 -0400 |
commit | 82486aa6f1b9bc8145e6d0fa2bc0b44307f3b875 (patch) | |
tree | 97674aade6f2ac755baebde5255a916028c50125 /mm | |
parent | 3013c4983eb15f4ce8958e81922cdfd80f771d3e (diff) |
ipv4: restore rt->fi for reference counting
IPv4 dst could use fi->fib_metrics to store metrics but fib_info
itself is refcnt'ed, so without taking a refcnt fi and
fi->fib_metrics could be freed while dst metrics still points to
it. This triggers use-after-free as reported by Andrey twice.
This patch reverts commit 2860583fe840 ("ipv4: Kill rt->fi") to
restore this reference counting. It is a quick fix for -net and
-stable, for -net-next, as Eric suggested, we can consider doing
reference counting for metrics itself instead of relying on fib_info.
IPv6 is very different, it copies or steals the metrics from mx6_config
in fib6_commit_metrics() so probably doesn't need a refcnt.
Decnet has already done the refcnt'ing, see dn_fib_semantic_match().
Fixes: 2860583fe840 ("ipv4: Kill rt->fi")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions