diff options
| author | Guillaume Nault <gnault@redhat.com> | 2022-02-04 16:58:16 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-02-08 07:12:46 +0300 |
| commit | f55fbb6afb8d701e3185e31e73f5ea9503a66744 (patch) | |
| tree | 884a144830e7b98ccf4fdf1e138b73aaff01e40a /net/ipv4/fib_frontend.c | |
| parent | 563f8e97e054451d167327336a53b7381517a998 (diff) | |
| download | linux-f55fbb6afb8d701e3185e31e73f5ea9503a66744.tar.xz | |
ipv4: Reject routes specifying ECN bits in rtm_tos
Use the new dscp_t type to replace the fc_tos field of fib_config, to
ensure IPv4 routes aren't influenced by ECN bits when configured with
non-zero rtm_tos.
Before this patch, IPv4 routes specifying an rtm_tos with some of the
ECN bits set were accepted. However they wouldn't work (never match) as
IPv4 normally clears the ECN bits with IPTOS_RT_MASK before doing a FIB
lookup (although a few buggy code paths don't).
After this patch, IPv4 routes specifying an rtm_tos with any ECN bit
set is rejected.
Note: IPv6 routes ignore rtm_tos altogether, any rtm_tos is accepted,
but treated as if it were 0.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/fib_frontend.c')
| -rw-r--r-- | net/ipv4/fib_frontend.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 4d61ddd8a0ec..c60e1d1ed2b0 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -32,6 +32,7 @@ #include <linux/list.h> #include <linux/slab.h> +#include <net/inet_dscp.h> #include <net/ip.h> #include <net/protocol.h> #include <net/route.h> @@ -735,8 +736,16 @@ static int rtm_to_fib_config(struct net *net, struct sk_buff *skb, memset(cfg, 0, sizeof(*cfg)); rtm = nlmsg_data(nlh); + + if (!inet_validate_dscp(rtm->rtm_tos)) { + NL_SET_ERR_MSG(extack, + "Invalid dsfield (tos): ECN bits must be 0"); + err = -EINVAL; + goto errout; + } + cfg->fc_dscp = inet_dsfield_to_dscp(rtm->rtm_tos); + cfg->fc_dst_len = rtm->rtm_dst_len; - cfg->fc_tos = rtm->rtm_tos; cfg->fc_table = rtm->rtm_table; cfg->fc_protocol = rtm->rtm_protocol; cfg->fc_scope = rtm->rtm_scope; |