Eric Dumazet 93636d1f1f netlink: netlink_diag_dump() runs without locks ... A recent commit removed locking from netlink_diag_dump() but forgot one error case. ===================================== [ BUG: bad unlock balance detected! ] 4.9.0-rc3+ #336 Not tainted ------------------------------------- syz-executor/4018 is trying to release lock ([ 36.220068] nl_table_lock ) at: [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182 but there are no more locks to release! other info that might help us debug this: 3 locks held by syz-executor/4018: #0: [ 36.220068] ( sock_diag_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40 #1: [ 36.220068] ( sock_diag_table_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0 #2: [ 36.220068] ( nlk->cb_mutex[ 36.220068] ){+.+.+.} , at: [ 36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0 stack backtrace: CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800 ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff Call Trace: [< inline >] __dump_stack lib/dump_stack.c:15 [<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51 [<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0 kernel/locking/lockdep.c:3388 [< inline >] __lock_release kernel/locking/lockdep.c:3512 [<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765 [< inline >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225 [<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255 [<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182 [<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110 Fixes: ad20207432 ("netlink: Use rhashtable walk interface in diag dump") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2016-11-03 16:16:51 -04:00
..
af_netlink.c	netlink: do not enter direct reclaim from netlink_dump()	2016-10-06 20:53:13 -04:00
af_netlink.h	net/netlink/af_netlink.h: Remove unused structure.	2016-06-09 22:26:24 -07:00
diag.c	netlink: netlink_diag_dump() runs without locks	2016-11-03 16:16:51 -04:00
genetlink.c	net: make genetlink ctrl ops const	2016-09-01 14:09:00 -07:00
Kconfig	netlink: remove mmapped netlink support	2016-02-18 11:42:18 -05:00
Makefile	netlink: Diag core and basic socket info dumping (v2)	2013-03-21 12:38:03 -04:00