diff options
author | David Ahern <dsahern@gmail.com> | 2020-01-10 09:03:58 -0800 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-01-10 11:36:36 -0800 |
commit | 9827c0634e461703abf81e8cc8b7adf5da5886d0 (patch) | |
tree | e0fe863e9f526b1dca445458610f1769b8c61696 /net | |
parent | b509750f8e87794c97dc199a92ea4e4e47db0b16 (diff) |
ipv4: Detect rollover in specific fib table dump
Sven-Haegar reported looping on fib dumps when 255.255.255.255 route has
been added to a table. The looping is caused by the key rolling over from
FFFFFFFF to 0. When dumping a specific table only, we need a means to detect
when the table dump is done. The key and count saved to cb args are both 0
only at the start of the table dump. If key is 0 and count > 0, then we are
in the rollover case. Detect and return to avoid looping.
This only affects dumps of a specific table; for dumps of all tables
(the case prior to the change in the Fixes tag) inet_dump_fib moved
the entry counter to the next table and reset the cb args used by
fib_table_dump and fn_trie_dump_leaf, so the rollover ffffffff back
to 0 did not cause looping with the dumps.
Fixes: effe67926624 ("net: Enable kernel side filtering of route dumps")
Reported-by: Sven-Haegar Koch <haegar@sdinet.de>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/ipv4/fib_trie.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index b9df9c09b84e..195469a13371 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -2193,6 +2193,12 @@ int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, int count = cb->args[2]; t_key key = cb->args[3]; + /* First time here, count and key are both always 0. Count > 0 + * and key == 0 means the dump has wrapped around and we are done. + */ + if (count && !key) + return skb->len; + while ((l = leaf_walk_rcu(&tp, key)) != NULL) { int err; |