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author | David Howells <dhowells@redhat.com> | 2020-01-30 21:50:36 +0000 |
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committer | David Howells <dhowells@redhat.com> | 2020-01-30 21:50:41 +0000 |
commit | 04d36d748fac349b068ef621611f454010054c58 (patch) | |
tree | 77b18f2ab733cda5c199ea289d3008df7726fa46 /net/rxrpc/conn_event.c | |
parent | f71dbf2fb28489a79bde0dca1c8adfb9cdb20a6b (diff) | |
download | linux-04d36d748fac349b068ef621611f454010054c58.tar.gz linux-04d36d748fac349b068ef621611f454010054c58.tar.bz2 linux-04d36d748fac349b068ef621611f454010054c58.zip |
rxrpc: Fix missing active use pinning of rxrpc_local object
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 <dhowells@redhat.com>
Diffstat (limited to 'net/rxrpc/conn_event.c')
-rw-r--r-- | net/rxrpc/conn_event.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index 808a4723f868..06fcff2ebbba 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -438,16 +438,12 @@ again: /* * connection-level event processor */ -void rxrpc_process_connection(struct work_struct *work) +static void rxrpc_do_process_connection(struct rxrpc_connection *conn) { - struct rxrpc_connection *conn = - container_of(work, struct rxrpc_connection, processor); struct sk_buff *skb; u32 abort_code = RX_PROTOCOL_ERROR; int ret; - rxrpc_see_connection(conn); - if (test_and_clear_bit(RXRPC_CONN_EV_CHALLENGE, &conn->events)) rxrpc_secure_connection(conn); @@ -475,18 +471,32 @@ void rxrpc_process_connection(struct work_struct *work) } } -out: - rxrpc_put_connection(conn); - _leave(""); return; requeue_and_leave: skb_queue_head(&conn->rx_queue, skb); - goto out; + return; protocol_error: if (rxrpc_abort_connection(conn, ret, abort_code) < 0) goto requeue_and_leave; rxrpc_free_skb(skb, rxrpc_skb_freed); - goto out; + return; +} + +void rxrpc_process_connection(struct work_struct *work) +{ + struct rxrpc_connection *conn = + container_of(work, struct rxrpc_connection, processor); + + rxrpc_see_connection(conn); + + if (__rxrpc_use_local(conn->params.local)) { + rxrpc_do_process_connection(conn); + rxrpc_unuse_local(conn->params.local); + } + + rxrpc_put_connection(conn); + _leave(""); + return; } |