<p>laforge has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/23979">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">Fix ipa_ccm_make_id_resp_from_req to work at all<br><br>The parser was so horribly broken, it could not ever have possibly<br>worked.<br><br>Change-Id: Ibed0ff7f8d36504ef783f2653c9982d4e25e874f<br>---<br>M src/gsm/ipa.c<br>1 file changed, 8 insertions(+), 3 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/79/23979/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/gsm/ipa.c b/src/gsm/ipa.c</span><br><span>index fdc0bc6..7379d06 100644</span><br><span>--- a/src/gsm/ipa.c</span><br><span>+++ b/src/gsm/ipa.c</span><br><span>@@ -412,10 +412,14 @@</span><br><span>     /* build a array of the IEIs */</span><br><span>      while (len >= 2) {</span><br><span>                uint8_t t_len, t_tag;</span><br><span style="color: hsl(0, 100%, 40%);">-           len -= 2;</span><br><span style="color: hsl(120, 100%, 40%);">+             len -= 2;       /* subtract the length of the two bytes read below */</span><br><span>                t_len = *cur++;</span><br><span>              t_tag = *cur++;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+           /* as the 'tag' is included in the length of t_len, this cannot happen */</span><br><span style="color: hsl(120, 100%, 40%);">+             if (t_len == 0)</span><br><span style="color: hsl(120, 100%, 40%);">+                       break;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span>             if (t_len > len + 1) {</span><br><span>                    LOGP(DLINP, LOGL_ERROR, "IPA CCM tag 0x%02x does not fit\n", t_tag);</span><br><span>                       break;</span><br><span>@@ -423,13 +427,14 @@</span><br><span> </span><br><span>           ies[num_ies++] = t_tag;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">-             cur += t_len;</span><br><span style="color: hsl(120, 100%, 40%);">+         /* we need to subtract one from t_len to account for the tag */</span><br><span style="color: hsl(120, 100%, 40%);">+               cur += t_len-1;</span><br><span>              /* prevent any unsigned integer underflow due to somebody sending us</span><br><span>                  * messages with wrong length values */</span><br><span>              if (len <= t_len)</span><br><span>                         len = 0;</span><br><span>             else</span><br><span style="color: hsl(0, 100%, 40%);">-                    len -= t_len;</span><br><span style="color: hsl(120, 100%, 40%);">+                 len -= t_len-1;</span><br><span>      }</span><br><span>    return ipa_ccm_make_id_resp(dev, ies, num_ies);</span><br><span> }</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/23979">change 23979</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/libosmocore/+/23979"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: Ibed0ff7f8d36504ef783f2653c9982d4e25e874f </div>
<div style="display:none"> Gerrit-Change-Number: 23979 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>