diff options
author | Pavel Skripkin <paskripkin@gmail.com> | 2021-10-24 16:13:56 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2021-10-26 16:47:12 +0300 |
commit | 6f68cd634856f8ca93bafd623ba5357e0f648c68 (patch) | |
tree | 6e79fd6203a535c10bd11391c9e6f51a7070a6eb /net/batman-adv/main.c | |
parent | fa40d9734a57bcbfa79a280189799f76c88f7bb0 (diff) | |
download | linux-6f68cd634856f8ca93bafd623ba5357e0f648c68.tar.xz |
net: batman-adv: fix error handling
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@google.com/ [1]
Reported-and-tested-by: syzbot+28b0702ada0bf7381f58@syzkaller.appspotmail.com
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/batman-adv/main.c')
-rw-r--r-- | net/batman-adv/main.c | 56 |
1 files changed, 40 insertions, 16 deletions
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 3ddd66e4c29e..5207cd8d6ad8 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -190,29 +190,41 @@ int batadv_mesh_init(struct net_device *soft_iface) 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); @@ -222,8 +234,20 @@ int batadv_mesh_init(struct net_device *soft_iface) 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; } |