4.19-stable review patch. If anyone has any objections, please let me know.
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From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit 143ece654f9f5b37bedea252a990be37e48ae3a5 ]
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 ying.xue@windriver.com Cc: Jon Maloy jon.maloy@ericsson.com Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Acked-by: Ying Xue ying.xue@windriver.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/tipc/socket.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-)
--- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -878,7 +878,6 @@ static int tipc_send_group_unicast(struc 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; @@ -892,7 +891,9 @@ static int tipc_send_group_unicast(struc /* 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;
@@ -922,7 +923,6 @@ static int tipc_send_group_anycast(struc 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; @@ -939,9 +939,10 @@ static int tipc_send_group_anycast(struc 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 */ @@ -950,7 +951,8 @@ static int tipc_send_group_anycast(struc &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) @@ -969,7 +971,8 @@ static int tipc_send_group_anycast(struc /* 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; @@ -1004,8 +1007,7 @@ static int tipc_send_group_bcast(struct 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); @@ -1018,8 +1020,9 @@ static int tipc_send_group_bcast(struct 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;
@@ -1034,7 +1037,7 @@ static int tipc_send_group_bcast(struct 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);