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authorPau Espin Pedrol <pespin@sysmocom.de>2020-01-08 21:10:04 +0100
committerPau Espin Pedrol <pespin@sysmocom.de>2020-01-08 21:10:08 +0100
commit7ec4c1f0ee2e4e04248cbb2d276094f8cb05ba6b (patch)
treec02731a4c481de17d2c813af91de84d59864e109
parenta468af2c64a85978a1d5e394539e900e3b3a2050 (diff)
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
-rw-r--r--src/sccp_scrc.c16
-rw-r--r--src/sccp_user.c1
2 files changed, 5 insertions, 12 deletions
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 @@ int sccp_scrc_rx_sclc_msg(struct osmo_sccp_instance *inst,
}
/* 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 @@ int scrc_rx_mtp_xfer_ind_xua(struct osmo_sccp_instance *inst,
/* 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 @@ int scrc_rx_mtp_xfer_ind_xua(struct osmo_sccp_instance *inst,
/* 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 @@ int scrc_rx_mtp_xfer_ind_xua(struct osmo_sccp_instance *inst,
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 @@ int scrc_rx_mtp_xfer_ind_xua(struct osmo_sccp_instance *inst,
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 @@ static int mtp_user_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
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",