[B.A.T.M.A.N.] [PATCH maint 1/2] batman-adv: Avoid storing non-TT-sync flags on singular entries too

[B.A.T.M.A.N.] [PATCH maint 1/2] batman-adv: Avoid storing non-TT-sync flags on singular entries too

[Linus Lüssing]

Since commit 382d020fe3fa ("batman-adv: fix TT sync flag inconsistencies")
TT sync flags and TT non-sync'd flags are supposed to be stored
separately.

The previous patch missed to apply this separation on a TT entry with
only a single TT orig entry.

This is a minor fix because with only a single TT orig entry the DDoS
issue the former patch solves does not apply.

Fixes: 382d020fe3fa ("batman-adv: fix TT sync flag inconsistencies")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---
 net/batman-adv/translation-table.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 39865513..61ce3000 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1705,7 +1705,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 		ether_addr_copy(common->addr, tt_addr);
 		common->vid = vid;
 
-		common->flags = flags;
+		common->flags = flags & (~BATADV_TT_SYNC_MASK);
+
 		tt_global_entry->roam_at = 0;
 		/* node must store current time in case of roaming. This is
 		 * needed to purge this entry out on timeout (if nobody claims
-- 
2.11.0

[B.A.T.M.A.N.] [PATCH maint 2/2] batman-adv: Fix multicast TT issues with bogus ROAM flags

[Linus Lüssing]

When a (broken) node wrongly sends multicast TT entries with a ROAM
flag then this causes any receiving node to drop all entries for the
same multicast MAC address announced by other nodes, leading to
packet loss.

Fix this DoS vector by only storing TT sync flags. For multicast TT
non-sync'ing flag bits like ROAM are unused so far anyway.

Fixes: 405cc1e5a81e ("batman-adv: Modified forwarding behaviour for multicast packets")
Reported-by: Leonardo Mörlein <me@irrelefant.net>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
---

Fixes: https://www.open-mesh.org/issues/355

The issue reported by Leonardo was reproduceable in a small, virtual test
setup with a ROAM flag injected on multicast TT entries by one node.
---
 net/batman-adv/translation-table.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index 61ce3000..12a2b7d2 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1705,7 +1705,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 		ether_addr_copy(common->addr, tt_addr);
 		common->vid = vid;
 
-		common->flags = flags & (~BATADV_TT_SYNC_MASK);
+		if (!is_multicast_ether_addr(common->addr))
+			common->flags = flags & (~BATADV_TT_SYNC_MASK);
 
 		tt_global_entry->roam_at = 0;
 		/* node must store current time in case of roaming. This is
@@ -1769,7 +1770,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
 		 * TT_CLIENT_TEMP, therefore they have to be copied in the
 		 * client entry
 		 */
-		common->flags |= flags & (~BATADV_TT_SYNC_MASK);
+		if (!is_multicast_ether_addr(common->addr))
+			common->flags |= flags & (~BATADV_TT_SYNC_MASK);
 
 		/* If there is the BATADV_TT_CLIENT_ROAM flag set, there is only
 		 * one originator left in the list and we previously received a
-- 
2.11.0

Re: [B.A.T.M.A.N.] [PATCH maint 2/2] batman-adv: Fix multicast TT issues with bogus ROAM flags

[Sven Eckelmann]

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On Donnerstag, 7. Juni 2018 00:46:24 CEST Linus Lüssing wrote:
> When a (broken) node wrongly sends multicast TT entries with a ROAM
> flag then this causes any receiving node to drop all entries for the
> same multicast MAC address announced by other nodes, leading to
> packet loss.
> 
> Fix this DoS vector by only storing TT sync flags. For multicast TT
> non-sync'ing flag bits like ROAM are unused so far anyway.
> 
> Fixes: 405cc1e5a81e ("batman-adv: Modified forwarding behaviour for multicast packets")
> Reported-by: Leonardo Mörlein <me@irrelefant.net>
> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>

Added as c7054ffae0c3 [1]

Thanks,
	Sven

[1] https://git.open-mesh.org/batman-adv.git/commit/c7054ffae0c3b08bb4bef3cffee1e0a543e14096

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Re: [B.A.T.M.A.N.] [PATCH maint 1/2] batman-adv: Avoid storing non-TT-sync flags on singular entries too

[Sven Eckelmann]

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On Donnerstag, 7. Juni 2018 00:46:23 CEST Linus Lüssing wrote:
> Since commit 382d020fe3fa ("batman-adv: fix TT sync flag inconsistencies")
> TT sync flags and TT non-sync'd flags are supposed to be stored
> separately.
> 
> The previous patch missed to apply this separation on a TT entry with
> only a single TT orig entry.
> 
> This is a minor fix because with only a single TT orig entry the DDoS
> issue the former patch solves does not apply.
> 
> Fixes: 382d020fe3fa ("batman-adv: fix TT sync flag inconsistencies")
> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
> ---
>  net/batman-adv/translation-table.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Added as beb6246b2339 [1]

Thanks,
	Sven

[1] https://git.open-mesh.org/batman-adv.git/commit/beb6246b2339852b6a429ae9259a8eb30a685041

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