kernel.git/net/tipc, branch linux-4.11.y

net: tipc: Fix a sleep-in-atomic bug in tipc_msg_reverse

2017-07-05T12:41:35Z

[ Upstream commit 343eba69c6968190d8654b857aea952fed9a6749 ] The kernel may sleep under a rcu read lock in tipc_msg_reverse, and the function call path is: tipc_l2_rcv_msg (acquire the lock by rcu_read_lock) tipc_rcv tipc_sk_rcv tipc_msg_reverse pskb_expand_head(GFP_KERNEL) --> may sleep tipc_node_broadcast tipc_node_xmit_skb tipc_node_xmit tipc_sk_rcv tipc_msg_reverse pskb_expand_head(GFP_KERNEL) --> may sleep To fix it, "GFP_KERNEL" is replaced with "GFP_ATOMIC". Signed-off-by: Jia-Ju Bai Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tipc: make macro tipc_wait_for_cond() smp safe

2017-06-07T10:10:00Z

[ Upstream commit 844cf763fba654436d3a4279b6a672c196cf1901 ] The macro tipc_wait_for_cond() is embedding the macro sk_wait_event() to fulfil its task. The latter, in turn, is evaluating the stated condition outside the socket lock context. This is problematic if the condition is accessing non-trivial data structures which may be altered by incoming interrupts, as is the case with the cong_links() linked list, used by socket to keep track of the current set of congested links. We sometimes see crashes when this list is accessed by a condition function at the same time as a SOCK_WAKEUP interrupt is removing an element from the list. We fix this by expanding selected parts of sk_wait_event() into the outer macro, while ensuring that all evaluations of a given condition are performed under socket lock protection. Fixes: commit 365ad353c256 ("tipc: reduce risk of user starvation during link congestion") Reviewed-by: Parthasarathy Bhuvaragan Signed-off-by: Jon Maloy Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tipc: close the connection if protocol messages contain errors

2017-04-28T16:20:42Z

When a socket is shutting down, we notify the peer node about the connection termination by reusing an incoming message if possible. If the last received message was a connection acknowledgment message, we reverse this message and set the error code to TIPC_ERR_NO_PORT and send it to peer. In tipc_sk_proto_rcv(), we never check for message errors while processing the connection acknowledgment or probe messages. Thus this message performs the usual flow control accounting and leaves the session hanging. In this commit, we terminate the connection when we receive such error messages. Signed-off-by: Parthasarathy Bhuvaragan Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: improve error validations for sockets in CONNECTING state

2017-04-28T16:20:42Z

Until now, the checks for sockets in CONNECTING state was based on the assumption that the incoming message was always from the peer's accepted data socket. However an application using a non-blocking socket sends an implicit connect, this socket which is in CONNECTING state can receive error messages from the peer's listening socket. As we discard these messages, the application socket hangs as there due to inactivity. In addition to this, there are other places where we process errors but do not notify the user. In this commit, we process such incoming error messages and notify our users about them using sk_state_change(). Signed-off-by: Parthasarathy Bhuvaragan Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: Fix missing connection request handling

2017-04-28T16:20:42Z

In filter_connect, we use waitqueue_active() to check for any connections to wakeup. But waitqueue_active() is missing memory barriers while accessing the critical sections, leading to inconsistent results. In this commit, we replace this with an SMP safe wq_has_sleeper() using the generic socket callback sk_data_ready(). Signed-off-by: Parthasarathy Bhuvaragan Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix socket flow control accounting error at tipc_recv_stream

2017-04-25T15:45:38Z

Until now in tipc_recv_stream(), we update the received unacknowledged bytes based on a stack variable and not based on the actual message size. If the user buffer passed at tipc_recv_stream() is smaller than the received skb, the size variable in stack differs from the actual message size in the skb. This leads to a flow control accounting error causing permanent congestion. In this commit, we fix this accounting error by always using the size of the incoming message. Fixes: 10724cc7bb78 ("tipc: redesign connection-level flow control") Signed-off-by: Parthasarathy Bhuvaragan Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix socket flow control accounting error at tipc_send_stream

2017-04-25T15:45:37Z

Until now in tipc_send_stream(), we return -1 when the socket encounters link congestion even if the socket had successfully sent partial data. This is incorrect as the application resends the same the partial data leading to data corruption at receiver's end. In this commit, we return the partially sent bytes as the return value at link congestion. Fixes: 10724cc7bb78 ("tipc: redesign connection-level flow control") Signed-off-by: Parthasarathy Bhuvaragan Reviewed-by: Jon Maloy Signed-off-by: David S. Miller

tipc: fix nametbl deadlock at tipc_nametbl_unsubscribe

2017-03-22T18:59:16Z

Until now, tipc_nametbl_unsubscribe() is called at subscriptions reference count cleanup. Usually the subscriptions cleanup is called at subscription timeout or at subscription cancel or at subscriber delete. We have ignored the possibility of this being called from other locations, which causes deadlock as we try to grab the tn->nametbl_lock while holding it already. CPU1: CPU2: ---------- ---------------- tipc_nametbl_publish spin_lock_bh(&tn->nametbl_lock) tipc_nametbl_insert_publ tipc_nameseq_insert_publ tipc_subscrp_report_overlap tipc_subscrp_get tipc_subscrp_send_event tipc_close_conn tipc_subscrb_release_cb tipc_subscrb_delete tipc_subscrp_put tipc_subscrp_put tipc_subscrp_kref_release tipc_nametbl_unsubscribe spin_lock_bh(&tn->nametbl_lock) <> CPU1: CPU2: ---------- ---------------- tipc_nametbl_stop spin_lock_bh(&tn->nametbl_lock) tipc_purge_publications tipc_nameseq_remove_publ tipc_subscrp_report_overlap tipc_subscrp_get tipc_subscrp_send_event tipc_close_conn tipc_subscrb_release_cb tipc_subscrb_delete tipc_subscrp_put tipc_subscrp_put tipc_subscrp_kref_release tipc_nametbl_unsubscribe spin_lock_bh(&tn->nametbl_lock) <> In this commit, we advance the calling of tipc_nametbl_unsubscribe() from the refcount cleanup to the intended callers. Fixes: d094c4d5f5c7 ("tipc: add subscription refcount to avoid invalid delete") Reported-by: John Thompson Acked-by: Jon Maloy Signed-off-by: Ying Xue Signed-off-by: Parthasarathy Bhuvaragan Signed-off-by: David S. Miller

net: Work around lockdep limitation in sockets that use sockets

2017-03-10T02:23:27Z

Lockdep issues a circular dependency warning when AFS issues an operation through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem. The theory lockdep comes up with is as follows: (1) If the pagefault handler decides it needs to read pages from AFS, it calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but creating a call requires the socket lock: mmap_sem must be taken before sk_lock-AF_RXRPC (2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind() binds the underlying UDP socket whilst holding its socket lock. inet_bind() takes its own socket lock: sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET (3) Reading from a TCP socket into a userspace buffer might cause a fault and thus cause the kernel to take the mmap_sem, but the TCP socket is locked whilst doing this: sk_lock-AF_INET must be taken before mmap_sem However, lockdep's theory is wrong in this instance because it deals only with lock classes and not individual locks. The AF_INET lock in (2) isn't really equivalent to the AF_INET lock in (3) as the former deals with a socket entirely internal to the kernel that never sees userspace. This is a limitation in the design of lockdep. Fix the general case by: (1) Double up all the locking keys used in sockets so that one set are used if the socket is created by userspace and the other set is used if the socket is created by the kernel. (2) Store the kern parameter passed to sk_alloc() in a variable in the sock struct (sk_kern_sock). This informs sock_lock_init(), sock_init_data() and sk_clone_lock() as to the lock keys to be used. Note that the child created by sk_clone_lock() inherits the parent's kern setting. (3) Add a 'kern' parameter to ->accept() that is analogous to the one passed in to ->create() that distinguishes whether kernel_accept() or sys_accept4() was the caller and can be passed to sk_alloc(). Note that a lot of accept functions merely dequeue an already allocated socket. I haven't touched these as the new socket already exists before we get the parameter. Note also that there are a couple of places where I've made the accepted socket unconditionally kernel-based: irda_accept() rds_rcp_accept_one() tcp_accept_from_sock() because they follow a sock_create_kern() and accept off of that. Whilst creating this, I noticed that lustre and ocfs don't create sockets through sock_create_kern() and thus they aren't marked as for-kernel, though they appear to be internal. I wonder if these should do that so that they use the new set of lock keys. Signed-off-by: David Howells Signed-off-by: David S. Miller

sched/headers: Prepare to move signal wakeup & sigpending methods from into

2017-03-02T07:42:32Z

Fix up affected files that include this signal functionality via sched.h. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar