<p>Harald Welte <strong>merged</strong> this change.</p><p><a href="https://gerrit.osmocom.org/9381">View Change</a></p><div style="white-space:pre-wrap">Approvals:
Jenkins Builder: Verified
Harald Welte: Looks good to me, approved
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">bsc_nat.c: Return correct err code to avoid heap-user-after-free<br><br>When ipaccess_bsc_read_cb calls bsc_close_connection, the osmo_fd<br>struct is freed, so we need to indicate to osmo_wqueue_bfd_cb that it<br>should not continue using the fd pointer after we return.<br><br>Fixes following AdressSanitizer report:<br><0015> openbsc/openbsc/src/osmo-bsc_nat/bsc_nat.c:1317 The connection to the BSC Nr: -1 was lost. Cleaning it<br>=================================================================<br>==27028==ERROR: AddressSanitizer: heap-use-after-free on address 0x6160000c521c at pc 0x7ffff606b056 bp 0x7fffffffe170 sp 0x7fffffffe168<br>READ of size 4 at 0x6160000c521c thread T0<br> #0 0x7ffff606b055 in osmo_wqueue_bfd_cb libosmocore/src/write_queue.c:65<br> #1 0x7ffff6055c3b in osmo_fd_disp_fds libosmocore/src/select.c:217<br> #2 0x7ffff6055ed5 in osmo_select_main libosmocore/src/select.c:257<br> #3 0x421c82 in main openbsc/openbsc/src/osmo-bsc_nat/bsc_nat.c:1713<br> #4 0x7ffff4803b44 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x21b44)<br> #5 0x406438 (/bin/osmo-bsc_nat+0x406438)<br><br>Fixes: OS#3300<br><br>Change-Id: I120f646601bd4275b9088d0d73000ce04564bc6b<br>---<br>M openbsc/src/osmo-bsc_nat/bsc_nat.c<br>1 file changed, 16 insertions(+), 15 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c b/openbsc/src/osmo-bsc_nat/bsc_nat.c</span><br><span>index 57b51a2..38a29be 100644</span><br><span>--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c</span><br><span>+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c</span><br><span>@@ -1308,20 +1308,18 @@</span><br><span> int ret;</span><br><span> </span><br><span> ret = ipa_msg_recv_buffered(bfd->fd, &msg, &bsc->pending_msg);</span><br><span style="color: hsl(0, 100%, 40%);">- if (ret <= 0) {</span><br><span style="color: hsl(0, 100%, 40%);">- if (ret == -EAGAIN)</span><br><span style="color: hsl(0, 100%, 40%);">- return 0;</span><br><span style="color: hsl(0, 100%, 40%);">- if (ret == 0)</span><br><span style="color: hsl(0, 100%, 40%);">- LOGP(DNAT, LOGL_ERROR,</span><br><span style="color: hsl(0, 100%, 40%);">- "The connection to the BSC Nr: %d was lost. Cleaning it\n",</span><br><span style="color: hsl(0, 100%, 40%);">- bsc->cfg ? bsc->cfg->nr : -1);</span><br><span style="color: hsl(0, 100%, 40%);">- else</span><br><span style="color: hsl(0, 100%, 40%);">- LOGP(DNAT, LOGL_ERROR,</span><br><span style="color: hsl(0, 100%, 40%);">- "Stream error on BSC Nr: %d. Failed to parse ip access message: %d (%s)\n",</span><br><span style="color: hsl(0, 100%, 40%);">- bsc->cfg ? bsc->cfg->nr : -1, ret, strerror(-ret));</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span style="color: hsl(0, 100%, 40%);">- bsc_close_connection(bsc);</span><br><span style="color: hsl(0, 100%, 40%);">- return -1;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (ret == -EAGAIN) {</span><br><span style="color: hsl(120, 100%, 40%);">+ return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (ret == 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DNAT, LOGL_ERROR,</span><br><span style="color: hsl(120, 100%, 40%);">+ "The connection to the BSC Nr: %d was lost. Cleaning it\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ bsc->cfg ? bsc->cfg->nr : -1);</span><br><span style="color: hsl(120, 100%, 40%);">+ goto close_fd;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else if (ret < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DNAT, LOGL_ERROR,</span><br><span style="color: hsl(120, 100%, 40%);">+ "Stream error on BSC Nr: %d. Failed to parse ip access message: %d (%s)\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ bsc->cfg ? bsc->cfg->nr : -1, ret, strerror(-ret));</span><br><span style="color: hsl(120, 100%, 40%);">+ goto close_fd;</span><br><span> }</span><br><span> </span><br><span> </span><br><span>@@ -1356,8 +1354,11 @@</span><br><span> /* FIXME: Currently no PONG is sent to the BSC */</span><br><span> /* FIXME: Currently no ID ACK is sent to the BSC */</span><br><span> forward_sccp_to_msc(bsc, msg);</span><br><span style="color: hsl(0, 100%, 40%);">-</span><br><span> return 0;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+close_fd:</span><br><span style="color: hsl(120, 100%, 40%);">+ bsc_close_connection(bsc);</span><br><span style="color: hsl(120, 100%, 40%);">+ return -EBADF;</span><br><span> }</span><br><span> </span><br><span> static int ipaccess_listen_bsc_cb(struct osmo_fd *bfd, unsigned int what)</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/9381">change 9381</a>. 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<div style="display:none"> Gerrit-Project: openbsc </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-MessageType: merged </div>
<div style="display:none"> Gerrit-Change-Id: I120f646601bd4275b9088d0d73000ce04564bc6b </div>
<div style="display:none"> Gerrit-Change-Number: 9381 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Pau Espin Pedrol <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: Harald Welte <laforge@gnumonks.org> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>