From: Pavel Skripkin <paskripkin@xxxxxxxxx> commit 6f68cd634856f8ca93bafd623ba5357e0f648c68 upstream. Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields. Link: https://lore.kernel.org/netdev/000000000000c87fbd05cef6bcb0@xxxxxxxxxx/ [1] Reported-and-tested-by: syzbot+28b0702ada0bf7381f58@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx> Acked-by: Sven Eckelmann <sven@xxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/batman-adv/bridge_loop_avoidance.c | 8 +++- net/batman-adv/main.c | 56 +++++++++++++++++++++++---------- net/batman-adv/network-coding.c | 4 +- net/batman-adv/translation-table.c | 4 +- 4 files changed, 52 insertions(+), 20 deletions(-) --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -1561,10 +1561,14 @@ int batadv_bla_init(struct batadv_priv * return 0; bat_priv->bla.claim_hash = batadv_hash_new(128); - bat_priv->bla.backbone_hash = batadv_hash_new(32); + if (!bat_priv->bla.claim_hash) + return -ENOMEM; - if (!bat_priv->bla.claim_hash || !bat_priv->bla.backbone_hash) + bat_priv->bla.backbone_hash = batadv_hash_new(32); + if (!bat_priv->bla.backbone_hash) { + batadv_hash_destroy(bat_priv->bla.claim_hash); return -ENOMEM; + } batadv_hash_set_lock_class(bat_priv->bla.claim_hash, &batadv_claim_hash_lock_class_key); --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -196,29 +196,41 @@ int batadv_mesh_init(struct net_device * bat_priv->gw.generation = 0; - ret = batadv_v_mesh_init(bat_priv); - if (ret < 0) - goto err; - ret = batadv_originator_init(bat_priv); - if (ret < 0) - goto err; + if (ret < 0) { + atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING); + goto err_orig; + } ret = batadv_tt_init(bat_priv); - if (ret < 0) - goto err; + if (ret < 0) { + atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING); + goto err_tt; + } + + ret = batadv_v_mesh_init(bat_priv); + if (ret < 0) { + atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING); + goto err_v; + } ret = batadv_bla_init(bat_priv); - if (ret < 0) - goto err; + if (ret < 0) { + atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING); + goto err_bla; + } ret = batadv_dat_init(bat_priv); - if (ret < 0) - goto err; + if (ret < 0) { + atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING); + goto err_dat; + } ret = batadv_nc_mesh_init(bat_priv); - if (ret < 0) - goto err; + if (ret < 0) { + atomic_set(&bat_priv->mesh_state, BATADV_MESH_DEACTIVATING); + goto err_nc; + } batadv_gw_init(bat_priv); batadv_mcast_init(bat_priv); @@ -228,8 +240,20 @@ int batadv_mesh_init(struct net_device * return 0; -err: - batadv_mesh_free(soft_iface); +err_nc: + batadv_dat_free(bat_priv); +err_dat: + batadv_bla_free(bat_priv); +err_bla: + batadv_v_mesh_free(bat_priv); +err_v: + batadv_tt_free(bat_priv); +err_tt: + batadv_originator_free(bat_priv); +err_orig: + batadv_purge_outstanding_packets(bat_priv, NULL); + atomic_set(&bat_priv->mesh_state, BATADV_MESH_INACTIVE); + return ret; } --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -155,8 +155,10 @@ int batadv_nc_mesh_init(struct batadv_pr &batadv_nc_coding_hash_lock_class_key); bat_priv->nc.decoding_hash = batadv_hash_new(128); - if (!bat_priv->nc.decoding_hash) + if (!bat_priv->nc.decoding_hash) { + batadv_hash_destroy(bat_priv->nc.coding_hash); goto err; + } batadv_hash_set_lock_class(bat_priv->nc.decoding_hash, &batadv_nc_decoding_hash_lock_class_key); --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -4405,8 +4405,10 @@ int batadv_tt_init(struct batadv_priv *b return ret; ret = batadv_tt_global_init(bat_priv); - if (ret < 0) + if (ret < 0) { + batadv_tt_local_table_free(bat_priv); return ret; + } batadv_tvlv_handler_register(bat_priv, batadv_tt_tvlv_ogm_handler_v1, batadv_tt_tvlv_unicast_handler_v1,
