On Tue, Oct 15, 2019 at 03:24:38PM +0800, Xin Long wrote: > syzbot reported a memory leak: > > BUG: memory leak, unreferenced object 0xffff888120b3d380 (size 64): > backtrace: > > [...] slab_alloc mm/slab.c:3319 [inline] > [...] kmem_cache_alloc+0x13f/0x2c0 mm/slab.c:3483 > [...] sctp_bucket_create net/sctp/socket.c:8523 [inline] > [...] sctp_get_port_local+0x189/0x5a0 net/sctp/socket.c:8270 > [...] sctp_do_bind+0xcc/0x200 net/sctp/socket.c:402 > [...] sctp_bindx_add+0x4b/0xd0 net/sctp/socket.c:497 > [...] sctp_setsockopt_bindx+0x156/0x1b0 net/sctp/socket.c:1022 > [...] sctp_setsockopt net/sctp/socket.c:4641 [inline] > [...] sctp_setsockopt+0xaea/0x2dc0 net/sctp/socket.c:4611 > [...] sock_common_setsockopt+0x38/0x50 net/core/sock.c:3147 > [...] __sys_setsockopt+0x10f/0x220 net/socket.c:2084 > [...] __do_sys_setsockopt net/socket.c:2100 [inline] > > It was caused by when sending msgs without binding a port, in the path: > inet_sendmsg() -> inet_send_prepare() -> inet_autobind() -> > .get_port/sctp_get_port(), sp->bind_hash will be set while bp->port is > not. Later when binding another port by sctp_setsockopt_bindx(), a new > bucket will be created as bp->port is not set. > > sctp's autobind is supposed to call sctp_autobind() where it does all > things including setting bp->port. Since sctp_autobind() is called in > sctp_sendmsg() if the sk is not yet bound, it should have skipped the > auto bind. > > THis patch is to avoid calling inet_autobind() in inet_send_prepare() > by changing sctp_prot .no_autobind with true, also remove the unused > .get_port. > > Reported-by: syzbot+d44f7bbebdea49dbc84a@xxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
