5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sven Eckelmann <sven@narfation.org>
commit 8d128c932bced74e3b1625ba3d7c78ef122a88a7 upstream.
When the mesh interface is getting deleted, then
batadv_bla_del_backbone_claims() (via batadv_bla_purge_backbone_gw()) could
make sure that all claims gets removed. But this function is only executed
when bat_priv->bla.claim_hash is not NULL. And since batadv_bla_free() is
always setting it to NULL before it is (indirectly) called, it was never
actually executed.
But the batadv_bla_purge_claims() -> batadv_handle_unclaim() is at the
moment too fragile because the BLA code is not handling the rehashing in
batadv_bla_update_orig_address(). The stored backbone address doesn't have
to be the one actually used for the hash bucket selection during the
initial adding of the backbone. The batadv_handle_unclaim() can therefore
fail to find the respective backbone for the unclaim and then stop the
deletion.
But the actual backbone_gw object is not needed for the unclaim because all
relevant information is always provided by the caller. And the check for
the existence of the backbone_gw doesn't provide any additional security
check for the deletion of a claim.
Cc: stable@kernel.org
Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/batman-adv/bridge_loop_avoidance.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
--- a/net/batman-adv/bridge_loop_avoidance.c
+++ b/net/batman-adv/bridge_loop_avoidance.c
@@ -940,26 +940,18 @@ static bool batadv_handle_unclaim(struct
u8 *backbone_addr, u8 *claim_addr,
unsigned short vid)
{
- struct batadv_bla_backbone_gw *backbone_gw;
-
/* unclaim in any case if it is our own */
if (primary_if && batadv_compare_eth(backbone_addr,
primary_if->net_dev->dev_addr))
batadv_bla_send_claim(bat_priv, claim_addr, vid,
BATADV_CLAIM_TYPE_UNCLAIM);
- backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid);
-
- if (!backbone_gw)
- return true;
-
/* this must be an UNCLAIM frame */
batadv_dbg(BATADV_DBG_BLA, bat_priv,
"%s(): UNCLAIM %pM on vid %d (sent by %pM)...\n", __func__,
- claim_addr, batadv_print_vid(vid), backbone_gw->orig);
+ claim_addr, batadv_print_vid(vid), backbone_addr);
batadv_bla_del_claim(bat_priv, claim_addr, vid);
- batadv_backbone_gw_put(backbone_gw);
return true;
}