On Sun, Mar 05, 2017 at 04:08:39PM +0100, Dmitry Vyukov wrote: > > -> #1 (genl_mutex){+.+.+.}: > validate_chain kernel/locking/lockdep.c:2267 [inline] > __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 > lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 > __mutex_lock_common kernel/locking/mutex.c:756 [inline] > __mutex_lock+0x172/0x1730 kernel/locking/mutex.c:893 > mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 > genl_lock net/netlink/genetlink.c:32 [inline] > genl_lock_dumpit+0x41/0x90 net/netlink/genetlink.c:478 > netlink_dump+0x54d/0xd40 net/netlink/af_netlink.c:2127 > __netlink_dump_start+0x4e5/0x760 net/netlink/af_netlink.c:2217 > genl_family_rcv_msg+0xd9d/0x1040 net/netlink/genetlink.c:546 > genl_rcv_msg+0xa6/0x140 net/netlink/genetlink.c:620 > netlink_rcv_skb+0x2ab/0x390 net/netlink/af_netlink.c:2298 > genl_rcv+0x28/0x40 net/netlink/genetlink.c:631 > netlink_unicast_kernel net/netlink/af_netlink.c:1231 [inline] > netlink_unicast+0x514/0x730 net/netlink/af_netlink.c:1257 > netlink_sendmsg+0xa9f/0xe50 net/netlink/af_netlink.c:1803 > sock_sendmsg_nosec net/socket.c:633 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:643 > sock_write_iter+0x326/0x600 net/socket.c:846 > call_write_iter include/linux/fs.h:1733 [inline] > new_sync_write fs/read_write.c:497 [inline] > __vfs_write+0x483/0x740 fs/read_write.c:510 > vfs_write+0x187/0x530 fs/read_write.c:558 > SYSC_write fs/read_write.c:605 [inline] > SyS_write+0xfb/0x230 fs/read_write.c:597 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > > -> #0 (nlk->cb_mutex){+.+.+.}: > check_prev_add kernel/locking/lockdep.c:1830 [inline] > check_prevs_add+0xa8f/0x19f0 kernel/locking/lockdep.c:1940 > validate_chain kernel/locking/lockdep.c:2267 [inline] > __lock_acquire+0x2149/0x3430 kernel/locking/lockdep.c:3340 > lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 > __mutex_lock_common kernel/locking/mutex.c:756 [inline] > __mutex_lock+0x172/0x1730 kernel/locking/mutex.c:893 > mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 > __netlink_dump_start+0xf4/0x760 net/netlink/af_netlink.c:2187 > netlink_dump_start include/linux/netlink.h:165 [inline] > crypto_user_rcv_msg+0x2ad/0x4f0 crypto/crypto_user.c:517 > netlink_rcv_skb+0x2ab/0x390 net/netlink/af_netlink.c:2298 > crypto_netlink_rcv+0x2a/0x40 crypto/crypto_user.c:538 > netlink_unicast_kernel net/netlink/af_netlink.c:1231 [inline] > netlink_unicast+0x514/0x730 net/netlink/af_netlink.c:1257 > netlink_sendmsg+0xa9f/0xe50 net/netlink/af_netlink.c:1803 > sock_sendmsg_nosec net/socket.c:633 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:643 > ___sys_sendmsg+0x8fa/0x9f0 net/socket.c:1985 > __sys_sendmsg+0x138/0x300 net/socket.c:2019 > SYSC_sendmsg net/socket.c:2030 [inline] > SyS_sendmsg+0x2d/0x50 net/socket.c:2026 > entry_SYSCALL_64_fastpath+0x1f/0xc2 This looks like a false positive. The cb_mutex in #1 is not the same as the cb_mutex in #0. The cb_mutex in #0 comes is obtained by crypto_user which uses straight netlink. The cb_mutex in #1 is a genl netlink socket. I'll have a look to see if we can annotate this. Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt