net: ipv4: fix table id in getroute response

[ Upstream commit 8a430ed50bb1b19ca14a46661f3b1b35f2fb5c39 ]

rtm_table is an 8-bit field while table ids are allowed up to u32. Commit
709772e6e065 ("net: Fix routing tables with id > 255 for legacy software")
added the preference to set rtm_table in dumps to RT_TABLE_COMPAT if the
table id is > 255. The table id returned on get route requests should do
the same.

Fixes: c36ba6603a11 ("net: Allow user to get table id from route lookup")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 7ceb8a574a50a0bfe38eb4796fa48502df5754e3..ef2f527a119b390e1e3e2697361af7bf5726e42f 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2430,7 +2430,7 @@ static int rt_fill_info(struct net *net,  __be32 dst, __be32 src, u32 table_id,
        r->rtm_dst_len  = 32;
        r->rtm_src_len  = 0;
        r->rtm_tos      = fl4->flowi4_tos;
-       r->rtm_table    = table_id;
+       r->rtm_table    = table_id < 256 ? table_id : RT_TABLE_COMPAT;
        if (nla_put_u32(skb, RTA_TABLE, table_id))
                goto nla_put_failure;
        r->rtm_type     = rt->rt_type;