<p>Vadim Yanitskiy has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/11254">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">layer23/l23sap.c: use safe wrapper around rsl_dec_chan_nr()<br><br>The rsl_dec_chan_nr() may fail to decode a given chan_nr, so it<br>could lead to uninitialized memory access. Let's avoid this by<br>adding a safe wrapper that.<br><br>Change-Id: Id78304f494be70aa05e2da11c785ba5d9aeaf6db<br>---<br>M src/host/layer23/src/common/l23sap.c<br>1 file changed, 38 insertions(+), 7 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmocom-bb refs/changes/54/11254/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/host/layer23/src/common/l23sap.c b/src/host/layer23/src/common/l23sap.c</span><br><span>index 5a3e79e..4560d23 100644</span><br><span>--- a/src/host/layer23/src/common/l23sap.c</span><br><span>+++ b/src/host/layer23/src/common/l23sap.c</span><br><span>@@ -49,11 +49,36 @@</span><br><span> </span><br><span> extern struct gsmtap_inst *gsmtap_inst;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/* Safe wrapper around rsl_dec_chan_nr() */</span><br><span style="color: hsl(120, 100%, 40%);">+static int l23sap_dec_chan_nr(uint8_t chan_nr, uint8_t link_id,</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t *chan_type, uint8_t *chan_ts, uint8_t *chan_ss,</span><br><span style="color: hsl(120, 100%, 40%);">+ uint8_t *gsmtap_chan_type)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ int rc;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ rc = rsl_dec_chan_nr(chan_nr, chan_type, chan_ss, chan_ts);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (rc) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DL23SAP, LOGL_ERROR, "Failed to decode logical channel "</span><br><span style="color: hsl(120, 100%, 40%);">+ "info (chan_nr=0x%02x, link_id=0x%02x)\n", chan_nr, link_id);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (gsmtap_chan_type)</span><br><span style="color: hsl(120, 100%, 40%);">+ *gsmtap_chan_type = GSMTAP_CHANNEL_UNKNOWN;</span><br><span style="color: hsl(120, 100%, 40%);">+ *chan_type = *chan_ss = *chan_ts = 0x00;</span><br><span style="color: hsl(120, 100%, 40%);">+ return -EINVAL;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Pick corresponding GSMTAP channel type */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (gsmtap_chan_type)</span><br><span style="color: hsl(120, 100%, 40%);">+ *gsmtap_chan_type = chantype_rsl2gsmtap(*chan_type, link_id);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> static int l23sap_check_dl_loss(struct osmocom_ms *ms,</span><br><span> struct l1ctl_info_dl *dl)</span><br><span> {</span><br><span> struct rx_meas_stat *meas = &ms->meas;</span><br><span> uint8_t chan_type, chan_ts, chan_ss;</span><br><span style="color: hsl(120, 100%, 40%);">+ int rc;</span><br><span> </span><br><span> /* Update measurements */</span><br><span> meas->last_fn = ntohl(dl->frame_nr);</span><br><span>@@ -62,7 +87,11 @@</span><br><span> meas->berr += dl->num_biterr;</span><br><span> meas->rxlev += dl->rx_level;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- rsl_dec_chan_nr(dl->chan_nr, &chan_type, &chan_ss, &chan_ts);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Attempt to decode logical channel info */</span><br><span style="color: hsl(120, 100%, 40%);">+ rc = l23sap_dec_chan_nr(dl->chan_nr, dl->link_id,</span><br><span style="color: hsl(120, 100%, 40%);">+ &chan_type, &chan_ts, &chan_ss, NULL);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (rc)</span><br><span style="color: hsl(120, 100%, 40%);">+ return rc;</span><br><span> </span><br><span> /* counting loss criteria */</span><br><span> if (!CHAN_IS_SACCH(dl->link_id)) {</span><br><span>@@ -138,9 +167,10 @@</span><br><span> signal_dbm = dl->rx_level - 110;</span><br><span> fn = ntohl(dl->frame_nr);</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* Logical channel info */</span><br><span style="color: hsl(0, 100%, 40%);">- rsl_dec_chan_nr(dl->chan_nr, &chan_type, &chan_ss, &chan_ts);</span><br><span style="color: hsl(0, 100%, 40%);">- gsmtap_chan_type = chantype_rsl2gsmtap(chan_type, dl->link_id);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Attempt to decode logical channel info */</span><br><span style="color: hsl(120, 100%, 40%);">+ l23sap_dec_chan_nr(dl->chan_nr, dl->link_id,</span><br><span style="color: hsl(120, 100%, 40%);">+ &chan_type, &chan_ts, &chan_ss,</span><br><span style="color: hsl(120, 100%, 40%);">+ &gsmtap_chan_type);</span><br><span> </span><br><span> /* Send to GSMTAP */</span><br><span> return gsmtap_send(gsmtap_inst, band_arfcn, chan_ts,</span><br><span>@@ -154,9 +184,10 @@</span><br><span> uint8_t chan_type, chan_ts, chan_ss;</span><br><span> uint8_t gsmtap_chan_type;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* send copy via GSMTAP */</span><br><span style="color: hsl(0, 100%, 40%);">- rsl_dec_chan_nr(ul->chan_nr, &chan_type, &chan_ss, &chan_ts);</span><br><span style="color: hsl(0, 100%, 40%);">- gsmtap_chan_type = chantype_rsl2gsmtap(chan_type, ul->link_id);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Attempt to decode logical channel info */</span><br><span style="color: hsl(120, 100%, 40%);">+ l23sap_dec_chan_nr(ul->chan_nr, ul->link_id,</span><br><span style="color: hsl(120, 100%, 40%);">+ &chan_type, &chan_ts, &chan_ss,</span><br><span style="color: hsl(120, 100%, 40%);">+ &gsmtap_chan_type);</span><br><span> </span><br><span> /**</span><br><span> * Send to GSMTAP</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/11254">change 11254</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/11254"/><meta itemprop="name" content="View Change"/></div></div>
<div style="display:none"> Gerrit-Project: osmocom-bb </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>
<div style="display:none"> Gerrit-Change-Id: Id78304f494be70aa05e2da11c785ba5d9aeaf6db </div>
<div style="display:none"> Gerrit-Change-Number: 11254 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Vadim Yanitskiy <axilirator@gmail.com> </div>