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From: Eric Blake <eblake@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Cc: qemu-block@nongnu.org, alex@alex.org.uk
Subject: Re: [Qemu-devel] [PATCH v4 04/11] nbd: Improve server handling of bogus commands
Date: Tue, 14 Jun 2016 12:24:41 -0600	[thread overview]
Message-ID: <57604BE9.80408@redhat.com> (raw)
In-Reply-To: <7c7619a2-a6f3-c30c-c8d0-aac1f96ae661@redhat.com>

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On 06/13/2016 06:19 AM, Paolo Bonzini wrote:
> 
> 
> On 12/05/2016 00:39, Eric Blake wrote:
>> We have a few bugs in how we handle invalid client commands:
>>
>> - A client can send an NBD_CMD_DISC where from + len overflows,
>> convincing us to reply with an error and stay connected, even
>> though the protocol requires us to silently disconnect. Fix by
>> hoisting the special case sooner.
>>

> It's simpler to always set req->complete.  Putting everything together:
> 
> diff --git a/nbd/server.c b/nbd/server.c

> @@ -1213,12 +1218,9 @@ static void nbd_trip(void *opaque)
>          LOG("invalid request type (%" PRIu32 ") received", request.type);
>          reply.error = EINVAL;
>      error_reply:
> -        /* We must disconnect after replying with an error to
> -         * NBD_CMD_READ, since we choose not to send bogus filler
> -         * data; likewise after NBD_CMD_WRITE if we did not read the
> -         * payload. */
> -        if (nbd_co_send_reply(req, &reply, 0) < 0 || command == NBD_CMD_READ ||
> -            (command == NBD_CMD_WRITE && !req->complete)) {
> +        /* We must disconnect after NBD_CMD_WRITE if we did not
> +         * read the payload. */
> +        if (nbd_co_send_reply(req, &reply, 0) < 0 || !req->complete)) {

This doesn't even compile (too many ')').  I assume you'll fix that
before your actual pull request goes out.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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  parent reply	other threads:[~2016-06-14 18:24 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-11 22:39 [Qemu-devel] [PATCH v4 00/11] nbd: tighter protocol compliance Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 01/11] nbd: Use BDRV_REQ_FUA for better FUA where supported Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 02/11] nbd: More debug typo fixes, use correct formats Eric Blake
2016-06-13 12:04   ` Paolo Bonzini
2016-06-13 12:21     ` Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 03/11] nbd: Quit server after any write error Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 04/11] nbd: Improve server handling of bogus commands Eric Blake
2016-06-13 12:10   ` Paolo Bonzini
2016-06-13 12:25     ` Eric Blake
2016-06-13 21:41       ` Alex Bligh
2016-06-14 13:32         ` Paolo Bonzini
2016-06-14 15:02           ` Alex Bligh
2016-06-14 15:11             ` Paolo Bonzini
2016-06-14 15:59               ` Alex Bligh
2016-06-14 22:05                 ` Paolo Bonzini
2016-06-15  7:05             ` [Qemu-devel] [Nbd] " Wouter Verhelst
2016-06-15  8:03               ` Wouter Verhelst
2016-06-15  8:52                 ` Alex Bligh
2016-06-15  9:18                   ` Paolo Bonzini
2016-06-15 10:27                     ` Alex Bligh
2016-06-15 10:34                       ` Paolo Bonzini
2016-06-15 12:13                       ` Wouter Verhelst
2016-06-15  7:02         ` Wouter Verhelst
2016-06-13 12:19   ` [Qemu-devel] " Paolo Bonzini
2016-06-13 16:54     ` Eric Blake
2016-06-14 18:24     ` Eric Blake [this message]
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 05/11] nbd: Reject unknown request flags Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 06/11] nbd: Group all Linux-specific ioctl code in one place Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 07/11] nbd: Clean up ioctl handling of qemu-nbd -c Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 08/11] nbd: Limit nbdflags to 16 bits Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 09/11] nbd: Add qemu-nbd -D for human-readable description Eric Blake
2016-05-12  7:47   ` Daniel P. Berrange
2016-05-12 15:38     ` Eric Blake
2016-05-12 15:51       ` Daniel P. Berrange
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 10/11] nbd: Detect servers that send unexpected error values Eric Blake
2016-05-11 22:39 ` [Qemu-devel] [PATCH v4 11/11] nbd: Avoid magic number for NBD max name size Eric Blake
2016-05-12 16:04 ` [Qemu-devel] [PATCH v4 00/11] nbd: tighter protocol compliance Alex Bligh
2016-06-01 23:02 ` Eric Blake
2016-06-13 16:28 ` Paolo Bonzini
2016-06-13 16:49   ` Eric Blake
2016-06-14 16:31     ` Paolo Bonzini

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