From: Eric Blake Date: Sun, 12 Nov 2017 01:39:36 +0000 (-0600) Subject: nbd: Don't crash when server reports NBD_CMD_READ failure X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=08ace1d75372b57c5ab56aea02c71cdda4b58fdf;p=qemu.git nbd: Don't crash when server reports NBD_CMD_READ failure If a server fails a read, for example with EIO, but the connection is still live, then we would crash trying to print a non-existent error message in nbd_client_co_preadv(). For consistency, also change the error printout in nbd_read_reply_entry(), although that instance does not crash. Bug introduced in commit f140e300. Signed-off-by: Eric Blake Message-Id: <20171112013936.5942-1-eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy --- diff --git a/block/nbd-client.c b/block/nbd-client.c index bcfed0133d..9206652e45 100644 --- a/block/nbd-client.c +++ b/block/nbd-client.c @@ -78,7 +78,7 @@ static coroutine_fn void nbd_read_reply_entry(void *opaque) while (!s->quit) { assert(s->reply.handle == 0); ret = nbd_receive_reply(s->ioc, &s->reply, &local_err); - if (ret < 0) { + if (local_err) { error_report_err(local_err); } if (ret <= 0) { @@ -691,7 +691,7 @@ int nbd_client_co_preadv(BlockDriverState *bs, uint64_t offset, ret = nbd_co_receive_cmdread_reply(client, request.handle, offset, qiov, &local_err); - if (ret < 0) { + if (local_err) { error_report_err(local_err); } return ret;