laforge has submitted this change. (
https://gerrit.osmocom.org/c/libosmo-sccp/+/16771 )
Change subject: sua.c: Avoid double free in
sua_rx_msg()->...->mtp_user_prim_cb()
......................................................................
sua.c: Avoid double free in sua_rx_msg()->...->mtp_user_prim_cb()
Old commit of mine successfully fixed a memory leak, but apparently
after some more investigation it seems to have introduced a double free
of xua object in other code paths.
Nowadays, it seems scrc_rx_mtp_xfer_ind_xua() is called from 3 different places:
mtp_user_prim_cb()
sua_rx_cl()
sua_rx_co()
Before present patch, first caller is not freeing the xua message and my
old commit made scrc_rx_mtp_xfer_ind_xua() free it (by passing
ownsership of the object). But the other 2 callers do free the xua
object afterwards (actually the grandparent caller sua_rx_msg() does
it), which means it would double-free the xua object.
Let's move ownership out of scrc_rx_mtp_xfer_ind_xua() and let the
caller free the xua object (only changes need on the first caller). This
way everybody is happy and we keep the free() closer to the alloc().
Change-Id: Ia550b781b97adbdc0a0ad58a1075e5467e056f1e
Related: OS#4348
Fixes: 9c3baa89fb6b3fc1ef588930f361d013f98a1e39
---
M src/sccp_scrc.c
M src/sccp_user.c
2 files changed, 5 insertions(+), 12 deletions(-)
Approvals:
Jenkins Builder: Verified
laforge: Looks good to me, approved
diff --git a/src/sccp_scrc.c b/src/sccp_scrc.c
index db49299..e259d7c 100644
--- a/src/sccp_scrc.c
+++ b/src/sccp_scrc.c
@@ -438,14 +438,13 @@
}
/* Figure C.1/Q.714 Sheet 1 of 12, after we converted the
- * MTP-TRANSFER.ind to SUA. Takes ownership of \a xua and frees it once
processed. */
+ * MTP-TRANSFER.ind to SUA. */
int scrc_rx_mtp_xfer_ind_xua(struct osmo_sccp_instance *inst,
struct xua_msg *xua)
{
struct osmo_sccp_addr called;
uint32_t proto_class;
struct xua_msg_part *hop_ctr_part;
- int rc;
LOGP(DLSS7, LOGL_DEBUG, "%s: %s\n", __func__, xua_msg_dump(xua,
&xua_dialect_sua));
/* TODO: SCCP or nodal congestion? */
@@ -455,7 +454,6 @@
/* Node 1 (Sheet 3) */
/* deliver to SCOC */
sccp_scoc_rx_from_scrc(inst, xua);
- xua_msg_free(xua);
return 0;
}
/* We only treat connectionless and CR below */
@@ -465,9 +463,7 @@
/* Route on GT? */
if (called.ri != OSMO_SCCP_RI_GT) {
/* Node 6 (Sheet 3) */
- rc = scrc_node_6(inst, xua, &called);
- xua_msg_free(xua);
- return rc;
+ return scrc_node_6(inst, xua, &called);
}
/* Message with hop-counter? */
hop_ctr_part = xua_msg_find_tag(xua, SUA_IEI_S7_HOP_CTR);
@@ -476,9 +472,7 @@
if (hop_counter <= 1) {
/* Error: hop-counter violation */
/* node 4 */
- rc = scrc_node_4(inst, xua,
SCCP_RETURN_CAUSE_HOP_COUNTER_VIOLATION);
- xua_msg_free(xua);
- return rc;
+ return scrc_node_4(inst, xua,
SCCP_RETURN_CAUSE_HOP_COUNTER_VIOLATION);
}
/* Decrement hop-counter */
hop_counter--;
@@ -498,7 +492,5 @@
default:
break;
}
- rc = scrc_translate_node_9(inst, xua, &called);
- xua_msg_free(xua);
- return rc;
+ return scrc_translate_node_9(inst, xua, &called);
}
diff --git a/src/sccp_user.c b/src/sccp_user.c
index 929445f..49cc212 100644
--- a/src/sccp_user.c
+++ b/src/sccp_user.c
@@ -174,6 +174,7 @@
xua->mtp = omp->u.transfer;
/* hand this primitive into SCCP via the SCRC code */
rc = scrc_rx_mtp_xfer_ind_xua(inst, xua);
+ xua_msg_free(xua);
break;
default:
LOGP(DLSCCP, LOGL_ERROR, "Unknown primitive %u:%u receivd\n",
--
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Gerrit-Project: libosmo-sccp
Gerrit-Branch: master
Gerrit-Change-Id: Ia550b781b97adbdc0a0ad58a1075e5467e056f1e
Gerrit-Change-Number: 16771
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pes...@sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: laforge <lafo...@osmocom.org>
Gerrit-MessageType: merged
