linux/net/batman-adv
Pavel Skripkin 6f68cd6348 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: c6c8fea297 ("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>
2021-10-26 14:47:12 +01:00
..
bat_algo.c batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bat_algo.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bat_iv_ogm.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
bat_iv_ogm.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bat_v_elp.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
bat_v_elp.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bat_v_ogm.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
bat_v_ogm.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bat_v.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
bat_v.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bitarray.c batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bitarray.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
bridge_loop_avoidance.c net: batman-adv: fix error handling 2021-10-26 14:47:12 +01:00
bridge_loop_avoidance.h batman-adv: Remove the repeated declaration 2021-05-30 13:38:27 +02:00
distributed-arp-table.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
distributed-arp-table.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
fragmentation.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
fragmentation.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
gateway_client.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
gateway_client.h batman-adv: Check ptr for NULL before reducing its refcnt 2021-08-08 20:21:40 +02:00
gateway_common.c batman-adv: Switch to kstrtox.h for kstrtou64 2021-08-08 20:05:46 +02:00
gateway_common.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
hard-interface.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
hard-interface.h batman-adv: Check ptr for NULL before reducing its refcnt 2021-08-08 20:21:40 +02:00
hash.c batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
hash.h batman-adv: Fix spelling mistakes 2021-06-02 08:46:03 +02:00
Kconfig This feature/cleanup patchset is an updated version of the pull request 2021-02-08 11:32:40 -08:00
log.c isystem: ship and use stdarg.h 2021-08-19 09:02:55 +09:00
log.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
main.c net: batman-adv: fix error handling 2021-10-26 14:47:12 +01:00
main.h batman-adv: Start new development cycle 2021-08-08 20:05:46 +02:00
Makefile batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
multicast.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
multicast.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
netlink.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
netlink.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
network-coding.c net: batman-adv: fix error handling 2021-10-26 14:47:12 +01:00
network-coding.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
originator.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
originator.h batman-adv: Check ptr for NULL before reducing its refcnt 2021-08-08 20:21:40 +02:00
routing.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
routing.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
send.c batman-adv: bcast: remove remaining skb-copy calls 2021-08-18 18:39:00 +02:00
send.h batman-adv: bcast: queue per interface, if needed 2021-05-17 12:00:44 +02:00
soft-interface.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
soft-interface.h batman-adv: Check ptr for NULL before reducing its refcnt 2021-08-08 20:21:40 +02:00
tp_meter.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
tp_meter.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
trace.c batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
trace.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
translation-table.c net: batman-adv: fix error handling 2021-10-26 14:47:12 +01:00
translation-table.h batman-adv: Check ptr for NULL before reducing its refcnt 2021-08-08 20:21:40 +02:00
tvlv.c batman-adv: Drop NULL check before dropping references 2021-08-08 20:21:40 +02:00
tvlv.h batman-adv: Drop publication years from copyright info 2021-02-06 09:22:10 +01:00
types.h batman-adv: Fix order of kernel doc in batadv_priv 2021-03-23 21:49:14 +01:00