wireguard-linux/net/rxrpc/peer_event.c, branch jd/orphan-parallel

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59Z

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

Merge tag 'rxrpc-fixes-20200605' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

2020-06-09T02:13:37Z

David Howells says: ==================== rxrpc: Fix hang due to missing notification Here's a fix for AF_RXRPC. Occasionally calls hang because there are circumstances in which rxrpc generate a notification when a call is completed - primarily because initial packet transmission failed and the call was killed off and an error returned. But the AFS filesystem driver doesn't check this under all circumstances, expecting failure to be delivered by asynchronous notification. There are two patches: the first moves the problematic bits out-of-line and the second contains the fix. ==================== Signed-off-by: David S. Miller

rxrpc: Fix missing notification

2020-06-05T12:36:35Z

Under some circumstances, rxrpc will fail a transmit a packet through the underlying UDP socket (ie. UDP sendmsg returns an error). This may result in a call getting stuck. In the instance being seen, where AFS tries to send a probe to the Volume Location server, tracepoints show the UDP Tx failure (in this case returing error 99 EADDRNOTAVAIL) and then nothing more: afs_make_vl_call: c=0000015d VL.GetCapabilities rxrpc_call: c=0000015d NWc u=1 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000dd89ee8a rxrpc_call: c=0000015d Gus u=2 sp=rxrpc_new_client_call+0x14f/0x580 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d SEE u=2 sp=rxrpc_activate_one_channel+0x7b/0x1c0 [rxrpc] a=00000000e20e4b08 rxrpc_call: c=0000015d CON u=2 sp=rxrpc_kernel_begin_call+0x106/0x170 [rxrpc] a=00000000e20e4b08 rxrpc_tx_fail: c=0000015d r=1 ret=-99 CallDataNofrag The problem is that if the initial packet fails and the retransmission timer hasn't been started, the call is set to completed and an error is returned from rxrpc_send_data_packet() to rxrpc_queue_packet(). Though rxrpc_instant_resend() is called, this does nothing because the call is marked completed. So rxrpc_notify_socket() isn't called and the error is passed back up to rxrpc_send_data(), rxrpc_kernel_send_data() and thence to afs_make_call() and afs_vl_get_capabilities() where it is simply ignored because it is assumed that the result of a probe will be collected asynchronously. Fileserver probing is similarly affected via afs_fs_get_capabilities(). Fix this by always issuing a notification in __rxrpc_set_call_completion() if it shifts a call to the completed state, even if an error is also returned to the caller through the function return value. Also put in a little bit of optimisation to avoid taking the call state_lock and disabling softirqs if the call is already in the completed state and remove some now redundant rxrpc_notify_socket() calls. Fixes: f5c17aaeb2ae ("rxrpc: Calls should only have one terminal state") Reported-by: Gerry Seidman Signed-off-by: David Howells Reviewed-by: Marc Dionne

rxrpc: Map the EACCES error produced by some ICMP6 to EHOSTUNREACH

2020-05-31T14:19:51Z

Map the EACCES error that is produced by some ICMP6 packets to EHOSTUNREACH when we get them as EACCES has other meanings within a filesystem context. Signed-off-by: David Howells

rxrpc: Fix the excessive initial retransmission timeout

2020-05-11T15:42:28Z

rxrpc currently uses a fixed 4s retransmission timeout until the RTT is sufficiently sampled. This can cause problems with some fileservers with calls to the cache manager in the afs filesystem being dropped from the fileserver because a packet goes missing and the retransmission timeout is greater than the call expiry timeout. Fix this by: (1) Copying the RTT/RTO calculation code from Linux's TCP implementation and altering it to fit rxrpc. (2) Altering the various users of the RTT to make use of the new SRTT value. (3) Replacing the use of rxrpc_resend_timeout to use the calculated RTO value instead (which is needed in jiffies), along with a backoff. Notes: (1) rxrpc provides RTT samples by matching the serial numbers on outgoing DATA packets that have the RXRPC_REQUEST_ACK set and PING ACK packets against the reference serial number in incoming REQUESTED ACK and PING-RESPONSE ACK packets. (2) Each packet that is transmitted on an rxrpc connection gets a new per-connection serial number, even for retransmissions, so an ACK can be cross-referenced to a specific trigger packet. This allows RTT information to be drawn from retransmitted DATA packets also. (3) rxrpc maintains the RTT/RTO state on the rxrpc_peer record rather than on an rxrpc_call because many RPC calls won't live long enough to generate more than one sample. (4) The calculated SRTT value is in units of 8ths of a microsecond rather than nanoseconds. The (S)RTT and RTO values are displayed in /proc/net/rxrpc/peers. Fixes: 17926a79320a ([AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both"") Signed-off-by: David Howells

rxrpc: Fix missing active use pinning of rxrpc_local object

2020-01-30T21:50:41Z

The introduction of a split between the reference count on rxrpc_local objects and the usage count didn't quite go far enough. A number of kernel work items need to make use of the socket to perform transmission. These also need to get an active count on the local object to prevent the socket from being closed. Fix this by getting the active count in those places. Also split out the raw active count get/put functions as these places tend to hold refs on the rxrpc_local object already, so getting and putting an extra object ref is just a waste of time. The problem can lead to symptoms like: BUG: kernel NULL pointer dereference, address: 0000000000000018 .. CPU: 2 PID: 818 Comm: kworker/u9:0 Not tainted 5.5.0-fscache+ #51 ... RIP: 0010:selinux_socket_sendmsg+0x5/0x13 ... Call Trace: security_socket_sendmsg+0x2c/0x3e sock_sendmsg+0x1a/0x46 rxrpc_send_keepalive+0x131/0x1ae rxrpc_peer_keepalive_worker+0x219/0x34b process_one_work+0x18e/0x271 worker_thread+0x1a3/0x247 kthread+0xe6/0xeb ret_from_fork+0x1f/0x30 Fixes: 730c5fd42c1e ("rxrpc: Fix local endpoint refcounting") Signed-off-by: David Howells

rxrpc: use rcu protection while reading sk->sk_user_data

2019-10-16T19:20:17Z

We need to extend the rcu_read_lock() section in rxrpc_error_report() and use rcu_dereference_sk_user_data() instead of plain access to sk->sk_user_data to make sure all rules are respected. The compiler wont reload sk->sk_user_data at will, and RCU rules prevent memory beeing freed too soon. Fixes: f0308fb07080 ("rxrpc: Fix possible NULL pointer access in ICMP handling") Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Signed-off-by: Eric Dumazet Cc: David Howells Signed-off-by: David S. Miller

rxrpc: Fix possible NULL pointer access in ICMP handling

2019-10-12T04:20:23Z

If an ICMP packet comes in on the UDP socket backing an AF_RXRPC socket as the UDP socket is being shut down, rxrpc_error_report() may get called to deal with it after sk_user_data on the UDP socket has been cleared, leading to a NULL pointer access when this local endpoint record gets accessed. Fix this by just returning immediately if sk_user_data was NULL. The oops looks like the following: #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page ... RIP: 0010:rxrpc_error_report+0x1bd/0x6a9 ... Call Trace: ? sock_queue_err_skb+0xbd/0xde ? __udp4_lib_err+0x313/0x34d __udp4_lib_err+0x313/0x34d icmp_unreach+0x1ee/0x207 icmp_rcv+0x25b/0x28f ip_protocol_deliver_rcu+0x95/0x10e ip_local_deliver+0xe9/0x148 __netif_receive_skb_one_core+0x52/0x6e process_backlog+0xdc/0x177 net_rx_action+0xf9/0x270 __do_softirq+0x1b6/0x39a ? smpboot_register_percpu_thread+0xce/0xce run_ksoftirqd+0x1d/0x42 smpboot_thread_fn+0x19e/0x1b3 kthread+0xf1/0xf6 ? kthread_delayed_work_timer_fn+0x83/0x83 ret_from_fork+0x24/0x30 Fixes: 17926a79320a ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both") Reported-by: syzbot+611164843bd48cc2190c@syzkaller.appspotmail.com Signed-off-by: David Howells Signed-off-by: David S. Miller

rxrpc: Use the tx-phase skb flag to simplify tracing

2019-08-27T09:04:18Z

Use the previously-added transmit-phase skbuff private flag to simplify the socket buffer tracing a bit. Which phase the skbuff comes from can now be divined from the skb rather than having to be guessed from the call state. We can also reduce the number of rxrpc_skb_trace values by eliminating the difference between Tx and Rx in the symbols. Signed-off-by: David Howells

rxrpc: Fix potential deadlock

2019-07-30T13:42:50Z

There is a potential deadlock in rxrpc_peer_keepalive_dispatch() whereby rxrpc_put_peer() is called with the peer_hash_lock held, but if it reduces the peer's refcount to 0, rxrpc_put_peer() calls __rxrpc_put_peer() - which the tries to take the already held lock. Fix this by providing a version of rxrpc_put_peer() that can be called in situations where the lock is already held. The bug may produce the following lockdep report: ============================================ WARNING: possible recursive locking detected 5.2.0-next-20190718 #41 Not tainted -------------------------------------------- kworker/0:3/21678 is trying to acquire lock: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh /./include/linux/spinlock.h:343 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: __rxrpc_put_peer /net/rxrpc/peer_object.c:415 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_put_peer+0x2d3/0x6a0 /net/rxrpc/peer_object.c:435 but task is already holding lock: 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: spin_lock_bh /./include/linux/spinlock.h:343 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_peer_keepalive_dispatch /net/rxrpc/peer_event.c:378 [inline] 00000000aa5eecdf (&(&rxnet->peer_hash_lock)->rlock){+.-.}, at: rxrpc_peer_keepalive_worker+0x6b3/0xd02 /net/rxrpc/peer_event.c:430 Fixes: 330bdcfadcee ("rxrpc: Fix the keepalive generator [ver #2]") Reported-by: syzbot+72af434e4b3417318f84@syzkaller.appspotmail.com Signed-off-by: David Howells Reviewed-by: Marc Dionne Reviewed-by: Jeffrey Altman