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authorDavid Howells <dhowells@redhat.com>2023-04-28 21:27:56 +0100
committerDavid S. Miller <davem@davemloft.net>2023-05-01 07:43:19 +0100
commitdb099c625b13a74d462521a46d98a8ce5b53af5d (patch)
tree8c3bb980a3aea4867c417293e26ad1ea777028c2 /net
parent0eb362d254814ce04848730bf32e75b8ee1a4d6c (diff)
rxrpc: Fix timeout of a call that hasn't yet been granted a channel
afs_make_call() calls rxrpc_kernel_begin_call() to begin a call (which may get stalled in the background waiting for a connection to become available); it then calls rxrpc_kernel_set_max_life() to set the timeouts - but that starts the call timer so the call timer might then expire before we get a connection assigned - leading to the following oops if the call stalled: BUG: kernel NULL pointer dereference, address: 0000000000000000 ... CPU: 1 PID: 5111 Comm: krxrpcio/0 Not tainted 6.3.0-rc7-build3+ #701 RIP: 0010:rxrpc_alloc_txbuf+0xc0/0x157 ... Call Trace: <TASK> rxrpc_send_ACK+0x50/0x13b rxrpc_input_call_event+0x16a/0x67d rxrpc_io_thread+0x1b6/0x45f ? _raw_spin_unlock_irqrestore+0x1f/0x35 ? rxrpc_input_packet+0x519/0x519 kthread+0xe7/0xef ? kthread_complete_and_exit+0x1b/0x1b ret_from_fork+0x22/0x30 Fix this by noting the timeouts in struct rxrpc_call when the call is created. The timer will be started when the first packet is transmitted. It shouldn't be possible to trigger this directly from userspace through AF_RXRPC as sendmsg() will return EBUSY if the call is in the waiting-for-conn state if it dropped out of the wait due to a signal. Fixes: 9d35d880e0e4 ("rxrpc: Move client call connection to the I/O thread") Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: "David S. Miller" <davem@davemloft.net> cc: Eric Dumazet <edumazet@google.com> cc: Jakub Kicinski <kuba@kernel.org> cc: Paolo Abeni <pabeni@redhat.com> cc: linux-afs@lists.infradead.org cc: netdev@vger.kernel.org cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/rxrpc/af_rxrpc.c3
-rw-r--r--net/rxrpc/ar-internal.h1
-rw-r--r--net/rxrpc/call_object.c9
-rw-r--r--net/rxrpc/sendmsg.c1
4 files changed, 13 insertions, 1 deletions
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index c32b164206f9..31f738d65f1c 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -265,6 +265,7 @@ static int rxrpc_listen(struct socket *sock, int backlog)
* @key: The security context to use (defaults to socket setting)
* @user_call_ID: The ID to use
* @tx_total_len: Total length of data to transmit during the call (or -1)
+ * @hard_timeout: The maximum lifespan of the call in sec
* @gfp: The allocation constraints
* @notify_rx: Where to send notifications instead of socket queue
* @upgrade: Request service upgrade for call
@@ -283,6 +284,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
struct key *key,
unsigned long user_call_ID,
s64 tx_total_len,
+ u32 hard_timeout,
gfp_t gfp,
rxrpc_notify_rx_t notify_rx,
bool upgrade,
@@ -313,6 +315,7 @@ struct rxrpc_call *rxrpc_kernel_begin_call(struct socket *sock,
p.tx_total_len = tx_total_len;
p.interruptibility = interruptibility;
p.kernel = true;
+ p.timeouts.hard = hard_timeout;
memset(&cp, 0, sizeof(cp));
cp.local = rx->local;
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 67b0a894162d..5d44dc08f66d 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -616,6 +616,7 @@ struct rxrpc_call {
unsigned long expect_term_by; /* When we expect call termination by */
u32 next_rx_timo; /* Timeout for next Rx packet (jif) */
u32 next_req_timo; /* Timeout for next Rx request packet (jif) */
+ u32 hard_timo; /* Maximum lifetime or 0 (jif) */
struct timer_list timer; /* Combined event timer */
struct work_struct destroyer; /* In-process-context destroyer */
rxrpc_notify_rx_t notify_rx; /* kernel service Rx notification function */
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index e9f1f49d18c2..fecbc73054bc 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -226,6 +226,13 @@ static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx,
if (cp->exclusive)
__set_bit(RXRPC_CALL_EXCLUSIVE, &call->flags);
+ if (p->timeouts.normal)
+ call->next_rx_timo = min(msecs_to_jiffies(p->timeouts.normal), 1UL);
+ if (p->timeouts.idle)
+ call->next_req_timo = min(msecs_to_jiffies(p->timeouts.idle), 1UL);
+ if (p->timeouts.hard)
+ call->hard_timo = p->timeouts.hard * HZ;
+
ret = rxrpc_init_client_call_security(call);
if (ret < 0) {
rxrpc_prefail_call(call, RXRPC_CALL_LOCAL_ERROR, ret);
@@ -257,7 +264,7 @@ void rxrpc_start_call_timer(struct rxrpc_call *call)
call->keepalive_at = j;
call->expect_rx_by = j;
call->expect_req_by = j;
- call->expect_term_by = j;
+ call->expect_term_by = j + call->hard_timo;
call->timer.expires = now;
}
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index c1b074c17b33..8e0b94714e84 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -651,6 +651,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
if (IS_ERR(call))
return PTR_ERR(call);
/* ... and we have the call lock. */
+ p.call.nr_timeouts = 0;
ret = 0;
if (rxrpc_call_is_complete(call))
goto out_put_unlock;