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Commit 143ece65 authored by Cong Wang's avatar Cong Wang Committed by David S. Miller
Browse files

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: default avatar <syzbot+10a9db47c3a0e13eb31c@syzkaller.appspotmail.com>
Fixes: b7d42635 ("tipc: introduce flow control for group broadcast messages")
Fixes: ee106d7f ("tipc: introduce group anycast messaging")
Fixes: 27bd9ec0 ("tipc: introduce group unicast messaging")
Cc: Ying Xue <ying.xue@windriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: default avatarCong Wang <xiyou.wangcong@gmail.com>
Acked-by: default avatarYing Xue <ying.xue@windriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 65cab850

net/tipc/socket.c

+14 −11
Original line number Diff line number Diff line
@@ -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);