From: David Howells dhowells@redhat.com
[ Upstream commit 2067b2b3f4846402a040286135f98f46f8919939 ]
Fix the service handler function for the CB.ProbeUuid RPC call so that it replies in the correct manner - that is an empty reply for success and an abort of 1 for failure.
Putting 0 or 1 in an integer in the body of the reply should result in the fileserver throwing an RX_PROTOCOL_ERROR abort and discarding its record of the client; older servers, however, don't necessarily check that all the data got consumed, and so might incorrectly think that they got a positive response and associate the client with the wrong host record.
If the client is incorrectly associated, this will result in callbacks intended for a different client being delivered to this one and then, when the other client connects and responds positively, all of the callback promises meant for the client that issued the improper response will be lost and it won't receive any further change notifications.
Fixes: 9396d496d745 ("afs: support the CB.ProbeUuid RPC op") Signed-off-by: David Howells dhowells@redhat.com Reviewed-by: Jeffrey Altman jaltman@auristor.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/afs/cmservice.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c index 3451be03667f0..00033a481ba05 100644 --- a/fs/afs/cmservice.c +++ b/fs/afs/cmservice.c @@ -502,18 +502,14 @@ static void SRXAFSCB_ProbeUuid(struct work_struct *work) struct afs_call *call = container_of(work, struct afs_call, work); struct afs_uuid *r = call->request;
- struct { - __be32 match; - } reply; - _enter("");
if (memcmp(r, &call->net->uuid, sizeof(call->net->uuid)) == 0) - reply.match = htonl(0); + afs_send_empty_reply(call); else - reply.match = htonl(1); + rxrpc_kernel_abort_call(call->net->socket, call->rxcall, + 1, 1, "K-1");
- afs_send_simple_reply(call, &reply, sizeof(reply)); afs_put_call(call); _leave(""); }