From: Ido Schimmel idosch@nvidia.com
[ Upstream commit 8a2618e14f81604a9b6ad305d57e0c8da939cd65 ]
Commit f96a3d74554d ("ipv4: Fix incorrect route flushing when source address is deleted") started to take the table ID field in the FIB info structure into account when determining if two structures are identical or not. This field is initialized using the 'fc_table' field in the route configuration structure, which is not set when adding a route via IOCTL.
The above can result in user space being able to install two identical routes that only differ in the table ID field of their associated FIB info.
Fix by initializing the table ID field in the route configuration structure in the IOCTL path.
Before the fix:
# ip route add default via 192.0.2.2 # route add default gw 192.0.2.2 # ip -4 r show default # default via 192.0.2.2 dev dummy10 # default via 192.0.2.2 dev dummy10
After the fix:
# ip route add default via 192.0.2.2 # route add default gw 192.0.2.2 SIOCADDRT: File exists # ip -4 r show default default via 192.0.2.2 dev dummy10
Audited the code paths to ensure there are no other paths that do not properly initialize the route configuration structure when installing a route.
Fixes: 5a56a0b3a45d ("net: Don't delete routes in different VRFs") Fixes: f96a3d74554d ("ipv4: Fix incorrect route flushing when source address is deleted") Reported-by: gaoxingwang gaoxingwang1@huawei.com Link: https://lore.kernel.org/netdev/20230314144159.2354729-1-gaoxingwang1@huawei.... Tested-by: gaoxingwang gaoxingwang1@huawei.com Signed-off-by: Ido Schimmel idosch@nvidia.com Reviewed-by: David Ahern dsahern@kernel.org Link: https://lore.kernel.org/r/20230315124009.4015212-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/fib_frontend.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 75c88d4863276..c21d57f02c651 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -573,6 +573,9 @@ static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt, cfg->fc_scope = RT_SCOPE_UNIVERSE; }
+ if (!cfg->fc_table) + cfg->fc_table = RT_TABLE_MAIN; + if (cmd == SIOCDELRT) return 0;