From 15ef70e286176165d28b0b8a969b422561a68dfc Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Mon, 10 Dec 2018 11:49:55 -0800 Subject: tipc: use lock_sock() in tipc_sk_reinit() lock_sock() must be used in process context to be race-free with other lock_sock() callers, for example, tipc_release(). Otherwise using the spinlock directly can't serialize a parallel tipc_release(). As it is blocking, we have to hold the sock refcnt before rhashtable_walk_stop() and release it after rhashtable_walk_start(). Fixes: 07f6c4bc048a ("tipc: convert tipc reference table to use generic rhashtable") Reported-by: Dmitry Vyukov Cc: Ying Xue Cc: Jon Maloy Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/tipc/socket.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/tipc/socket.c') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index b57b1be7252b..e1396fb87779 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -2724,11 +2724,15 @@ void tipc_sk_reinit(struct net *net) rhashtable_walk_start(&iter); while ((tsk = rhashtable_walk_next(&iter)) && !IS_ERR(tsk)) { - spin_lock_bh(&tsk->sk.sk_lock.slock); + sock_hold(&tsk->sk); + rhashtable_walk_stop(&iter); + lock_sock(&tsk->sk); msg = &tsk->phdr; msg_set_prevnode(msg, tipc_own_addr(net)); msg_set_orignode(msg, tipc_own_addr(net)); - spin_unlock_bh(&tsk->sk.sk_lock.slock); + release_sock(&tsk->sk); + rhashtable_walk_start(&iter); + sock_put(&tsk->sk); } rhashtable_walk_stop(&iter); -- cgit v1.2.3 From 143ece654f9f5b37bedea252a990be37e48ae3a5 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Tue, 11 Dec 2018 21:43:51 -0800 Subject: tipc: check tsk->group in tipc_wait_for_cond() tipc_wait_for_cond() drops socket lock before going to sleep, but tsk->group could be freed right after that release_sock(). So we have to re-check and reload tsk->group after it wakes up. After this patch, tipc_wait_for_cond() returns -ERESTARTSYS when tsk->group is NULL, instead of continuing with the assumption of a non-NULL tsk->group. (It looks like 'dsts' should be re-checked and reloaded too, but it is a different bug.) Similar for tipc_send_group_unicast() and tipc_send_group_anycast(). Reported-by: syzbot+10a9db47c3a0e13eb31c@syzkaller.appspotmail.com Fixes: b7d42635517f ("tipc: introduce flow control for group broadcast messages") Fixes: ee106d7f942d ("tipc: introduce group anycast messaging") Fixes: 27bd9ec027f3 ("tipc: introduce group unicast messaging") Cc: Ying Xue Cc: Jon Maloy Signed-off-by: Cong Wang Acked-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/socket.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) (limited to 'net/tipc/socket.c') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index e1396fb87779..656940692a44 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -880,7 +880,6 @@ static int tipc_send_group_unicast(struct socket *sock, struct msghdr *m, DECLARE_SOCKADDR(struct sockaddr_tipc *, dest, m->msg_name); int blks = tsk_blocks(GROUP_H_SIZE + dlen); struct tipc_sock *tsk = tipc_sk(sk); - struct tipc_group *grp = tsk->group; struct net *net = sock_net(sk); struct tipc_member *mb = NULL; u32 node, port; @@ -894,7 +893,9 @@ static int tipc_send_group_unicast(struct socket *sock, struct msghdr *m, /* Block or return if destination link or member is congested */ rc = tipc_wait_for_cond(sock, &timeout, !tipc_dest_find(&tsk->cong_links, node, 0) && - !tipc_group_cong(grp, node, port, blks, &mb)); + tsk->group && + !tipc_group_cong(tsk->group, node, port, blks, + &mb)); if (unlikely(rc)) return rc; @@ -924,7 +925,6 @@ static int tipc_send_group_anycast(struct socket *sock, struct msghdr *m, struct tipc_sock *tsk = tipc_sk(sk); struct list_head *cong_links = &tsk->cong_links; int blks = tsk_blocks(GROUP_H_SIZE + dlen); - struct tipc_group *grp = tsk->group; struct tipc_msg *hdr = &tsk->phdr; struct tipc_member *first = NULL; struct tipc_member *mbr = NULL; @@ -941,9 +941,10 @@ static int tipc_send_group_anycast(struct socket *sock, struct msghdr *m, type = msg_nametype(hdr); inst = dest->addr.name.name.instance; scope = msg_lookup_scope(hdr); - exclude = tipc_group_exclude(grp); while (++lookups < 4) { + exclude = tipc_group_exclude(tsk->group); + first = NULL; /* Look for a non-congested destination member, if any */ @@ -952,7 +953,8 @@ static int tipc_send_group_anycast(struct socket *sock, struct msghdr *m, &dstcnt, exclude, false)) return -EHOSTUNREACH; tipc_dest_pop(&dsts, &node, &port); - cong = tipc_group_cong(grp, node, port, blks, &mbr); + cong = tipc_group_cong(tsk->group, node, port, blks, + &mbr); if (!cong) break; if (mbr == first) @@ -971,7 +973,8 @@ static int tipc_send_group_anycast(struct socket *sock, struct msghdr *m, /* Block or return if destination link or member is congested */ rc = tipc_wait_for_cond(sock, &timeout, !tipc_dest_find(cong_links, node, 0) && - !tipc_group_cong(grp, node, port, + tsk->group && + !tipc_group_cong(tsk->group, node, port, blks, &mbr)); if (unlikely(rc)) return rc; @@ -1006,8 +1009,7 @@ static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m, struct sock *sk = sock->sk; struct net *net = sock_net(sk); struct tipc_sock *tsk = tipc_sk(sk); - struct tipc_group *grp = tsk->group; - struct tipc_nlist *dsts = tipc_group_dests(grp); + struct tipc_nlist *dsts = tipc_group_dests(tsk->group); struct tipc_mc_method *method = &tsk->mc_method; bool ack = method->mandatory && method->rcast; int blks = tsk_blocks(MCAST_H_SIZE + dlen); @@ -1020,8 +1022,9 @@ static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m, return -EHOSTUNREACH; /* Block or return if any destination link or member is congested */ - rc = tipc_wait_for_cond(sock, &timeout, !tsk->cong_link_cnt && - !tipc_group_bc_cong(grp, blks)); + rc = tipc_wait_for_cond(sock, &timeout, + !tsk->cong_link_cnt && tsk->group && + !tipc_group_bc_cong(tsk->group, blks)); if (unlikely(rc)) return rc; @@ -1036,7 +1039,7 @@ static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m, msg_set_hdr_sz(hdr, GROUP_H_SIZE); msg_set_destport(hdr, 0); msg_set_destnode(hdr, 0); - msg_set_grp_bc_seqno(hdr, tipc_group_bc_snd_nxt(grp)); + msg_set_grp_bc_seqno(hdr, tipc_group_bc_snd_nxt(tsk->group)); /* Avoid getting stuck with repeated forced replicasts */ msg_set_grp_bc_ack_req(hdr, ack); -- cgit v1.2.3 From 3c6306d44082ef007a258ae1b86ea58e6974ee3f Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sun, 16 Dec 2018 23:25:12 -0800 Subject: tipc: check group dests after tipc_wait_for_cond() Similar to commit 143ece654f9f ("tipc: check tsk->group in tipc_wait_for_cond()") we have to reload grp->dests too after we re-take the sock lock. This means we need to move the dsts check after tipc_wait_for_cond() too. Fixes: 75da2163dbb6 ("tipc: introduce communication groups") Reported-and-tested-by: syzbot+99f20222fc5018d2b97a@syzkaller.appspotmail.com Cc: Ying Xue Cc: Jon Maloy Signed-off-by: Cong Wang Acked-by: Jon Maloy Signed-off-by: David S. Miller --- net/tipc/socket.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'net/tipc/socket.c') diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 656940692a44..8f34db2a9785 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1009,7 +1009,7 @@ static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m, struct sock *sk = sock->sk; struct net *net = sock_net(sk); struct tipc_sock *tsk = tipc_sk(sk); - struct tipc_nlist *dsts = tipc_group_dests(tsk->group); + struct tipc_nlist *dsts; struct tipc_mc_method *method = &tsk->mc_method; bool ack = method->mandatory && method->rcast; int blks = tsk_blocks(MCAST_H_SIZE + dlen); @@ -1018,9 +1018,6 @@ static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m, struct sk_buff_head pkts; int rc = -EHOSTUNREACH; - if (!dsts->local && !dsts->remote) - return -EHOSTUNREACH; - /* Block or return if any destination link or member is congested */ rc = tipc_wait_for_cond(sock, &timeout, !tsk->cong_link_cnt && tsk->group && @@ -1028,6 +1025,10 @@ static int tipc_send_group_bcast(struct socket *sock, struct msghdr *m, if (unlikely(rc)) return rc; + dsts = tipc_group_dests(tsk->group); + if (!dsts->local && !dsts->remote) + return -EHOSTUNREACH; + /* Complete message header */ if (dest) { msg_set_type(hdr, TIPC_GRP_MCAST_MSG); -- cgit v1.2.3