netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: David Ahern <dsahern@kernel.org>
To: kuba@kernel.org, davem@davemloft.net, pabeni@redhat.com
Cc: netdev@vger.kernel.org, idosch@idosch.org,
	David Ahern <dsahern@kernel.org>,
	Gwangun Jung <exsociety@gmail.com>
Subject: [PATCH net] ipv4: Handle attempt to delete multipath route when fib_info contains an nh reference
Date: Wed,  5 Oct 2022 12:12:57 -0600	[thread overview]
Message-ID: <20221005181257.8897-1-dsahern@kernel.org> (raw)

Gwangun Jung reported a slab-out-of-bounds access in fib_nh_match:
    fib_nh_match+0xf98/0x1130 linux-6.0-rc7/net/ipv4/fib_semantics.c:961
    fib_table_delete+0x5f3/0xa40 linux-6.0-rc7/net/ipv4/fib_trie.c:1753
    inet_rtm_delroute+0x2b3/0x380 linux-6.0-rc7/net/ipv4/fib_frontend.c:874

Separate nexthop objects are mutually exclusive with the legacy
multipath spec. Fix fib_nh_match to return if the config for the
to be deleted route contains a multipath spec while the fib_info
is using a nexthop object.

Fixes: 493ced1ac47c ("ipv4: Allow routes to use nexthop objects")
Reported-by: Gwangun Jung <exsociety@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
---
 net/ipv4/fib_semantics.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 2dc97583d279..17caa73f57e6 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -926,6 +926,10 @@ int fib_nh_match(struct net *net, struct fib_config *cfg, struct fib_info *fi,
 	if (!cfg->fc_mp)
 		return 0;
 
+	/* multipath spec and nexthop id are mutually exclusive */
+	if (fi->nh)
+		return 1;
+
 	rtnh = cfg->fc_mp;
 	remaining = cfg->fc_mp_len;
 
-- 
2.25.1


             reply	other threads:[~2022-10-05 18:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-05 18:12 David Ahern [this message]
2022-10-05 19:08 ` [PATCH net] ipv4: Handle attempt to delete multipath route when fib_info contains an nh reference Ido Schimmel
2022-10-05 19:27   ` David Ahern
2022-10-06  6:49     ` Ido Schimmel
2022-10-06  7:29       ` Paolo Abeni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20221005181257.8897-1-dsahern@kernel.org \
    --to=dsahern@kernel.org \
    --cc=davem@davemloft.net \
    --cc=exsociety@gmail.com \
    --cc=idosch@idosch.org \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=pabeni@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).