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List: cifs-protocol
Subject: Re: [cifs-protocol] [REG:119070521001876] SMB3 LZ77 decompression issues
From: Edgar Olougouna via cifs-protocol <cifs-protocol () lists ! samba ! org>
Date: 2019-07-15 14:49:25
Message-ID: DM6PR21MB12090D7081BFF232240CAB2FDBCF0 () DM6PR21MB1209 ! namprd21 ! prod ! outlook ! com
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Metze,
You observation is correct. It should be 4 bytes, instead of 8 bytes. Thanks for \
catching! 37
+
If MatchLength == 0
38
+
MatchLength = read 4 bytes from InputPosition
39
+
InputPosition += 4 bytes
Thanks,
Edgar
-----Original Message-----
From: Stefan Metzmacher <metze@samba.org>
Sent: Monday, July 15, 2019 3:14 AM
To: Edgar Olougouna <edgaro@microsoft.com>; Aurélien Aptel <aaptel@suse.com>; \
cifs-protocol@lists.samba.org
Cc: support <support@mail.support.microsoft.com>
Subject: Re: [cifs-protocol] [REG:119070521001876] SMB3 LZ77 decompression issues
Hi Edgar,
> Upon review, we noticed there is additional logic to handle values larger than 1 << \
> 16 for the MatchLength. The second change here is that the we subtract 15 from the \
> MatchLength instead of 15 + 7. See additions on lines 37 to 39. Let us know \
> whether this helps.
> 37
> +
> If MatchLength == 0
> 38
> +
> MatchLength = read 8 bytes from InputPosition
> 39
> +
> InputPosition += 8 bytes
Shouldn't this be 4 bytes instead of 8?
metze
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<p class="MsoPlainText">Metze,<o:p></o:p></p>
<p class="MsoPlainText">You observation is correct. It should be 4 bytes, instead of \
8 bytes. Thanks for catching!<o:p></o:p></p> <p class="MsoPlainText"><o:p></o:p></p>
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bsp; If \
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style="font-size:10.0pt;font-family:Consolas;color:black"> &nbs \
p; MatchLength \
= read 4 bytes from InputPosition</span><span \
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#CCCCCC 1.0pt;background:#FFFF66;padding:0in 0in 0in 0in"> <p class="MsoNormal"><span \
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p; InputPosition \
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<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Thanks,<o:p></o:p></p>
<p class="MsoPlainText">Edgar<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">-----Original Message-----<br>
From: Stefan Metzmacher <metze@samba.org> <br>
Sent: Monday, July 15, 2019 3:14 AM<br>
To: Edgar Olougouna <edgaro@microsoft.com>; Aurélien Aptel \
<aaptel@suse.com>; cifs-protocol@lists.samba.org<br>
Cc: support <support@mail.support.microsoft.com><br>
Subject: Re: [cifs-protocol] [REG:119070521001876] SMB3 LZ77 decompression issues</p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">Hi Edgar,<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">> Upon review, we noticed there is additional logic to \
handle values larger than 1 << 16 for the MatchLength. The second change here \
is that the we subtract 15 from the MatchLength instead of 15 + 7. See \
additions on lines 37 to 39. Let us know whether this helps.<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">> 37<o:p></o:p></p>
<p class="MsoPlainText">> +<o:p></o:p></p>
<p class="MsoPlainText">> \
If MatchLength == 0<o:p></o:p></p> <p class="MsoPlainText">> 38<o:p></o:p></p>
<p class="MsoPlainText">> +<o:p></o:p></p>
<p class="MsoPlainText">> &nbs \
p; \
MatchLength = read 8 bytes from InputPosition<o:p></o:p></p> <p \
class="MsoPlainText">> 39<o:p></o:p></p> <p class="MsoPlainText">> \
+<o:p></o:p></p> <p \
class="MsoPlainText">> & \
nbsp; \
InputPosition += 8 bytes<o:p></o:p></p> <p \
class="MsoPlainText"><o:p> </o:p></p> <p class="MsoPlainText">Shouldn't this be \
4 bytes instead of 8?<o:p></o:p></p> <p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText">metze<o:p></o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
<p class="MsoPlainText"><o:p> </o:p></p>
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