[S] Change in libosmo-sigtran[pespin/rel-2.1.0]: asp: Avoid double-free of received msg if conn is teared down

pespin has uploaded this change for review. ( https://gerrit.osmocom.org/c/libosmo-sigtran/+/40403?usp=email ) Change subject: asp: Avoid double-free of received msg if conn is teared down ...................................................................... asp: Avoid double-free of received msg if conn is teared down """ 20250516192255921 DLSS7 DEBUG IPA_ASP(ipa-asp-loadshare-sender0){WAIT_ID_RESP}: Received Event IPA_CCM_ID_RESP (ipa.c:120) 20250516192255921 DLMI DEBUG Rx IPA CCM ID_RESP: Unit_ID='0/1/2' MAC_Address='' Location_1='' Location_2='' Equipment_Version='' Software_Version='' Unit_Name='mahlzeit' Serial_Number='' (ipa.c:233) 20250516192255921 DLSS7 NOTICE IPA_ASP(ipa-asp-loadshare-sender0){WAIT_ID_RESP}: Cannot find any definition for IPA Unit Name 'mahlzeit' (xua_asp_fsm.c:968) 20250516192255921 DLSS7 INFO ipa-asp-loadshare-sender0: connection closed (ss7_asp.c:1159) 20250516192255921 DLSS7 DEBUG IPA_ASP(ipa-asp-loadshare-sender0){WAIT_ID_RESP}: Received Event SCTP-COMM_DOWN.ind (ss7_asp.c:1165) 20250516192255922 DLSS7 DEBUG IPA_ASP(ipa-asp-loadshare-sender0){WAIT_ID_RESP}: state_chg to ASP_DOWN (xua_asp_fsm.c:1154) 20250516192255922 DLSS7 DEBUG XUA_AS(ipa-as-loadshare-sender){AS_DOWN}: Received Event ASPAS-ASP_DOWN.ind (xua_asp_fsm.c:370) 20250516192255922 DLSS7 DEBUG IPA_ASP(ipa-asp-loadshare-sender0){ASP_DOWN}: No Layer Manager, dropping M-ASP_DOWN.indication (xua_asp_fsm.c:119) 20250516192255922 DLSS7 DEBUG IPA_ASP(ipa-asp-loadshare-sender0){ASP_DOWN}: No Layer Manager, dropping M-SCTP_RELEASE.indication (xua_asp_fsm.c:119) Program terminated with signal SIGABRT, Aborted. #0 0x000076bb9898ceec in ?? () from /lib/x86_64-linux-gnu/libc.so.6 #0 0x000076bb9898ceec in ?? () from /lib/x86_64-linux-gnu/libc.so.6 #1 0x000076bb9893dfb2 in raise () from /lib/x86_64-linux-gnu/libc.so.6 #2 0x000076bb98928472 in abort () from /lib/x86_64-linux-gnu/libc.so.6 #3 0x000076bb98ae6496 in ?? () from /lib/x86_64-linux-gnu/libtalloc.so.2 #4 0x000076bb98b1b869 in msgb_free (m=0x5f957de3e750) at ../../../src_copy/libosmocore/src/core/msgb.c:119 #5 0x000076bb98bab8c8 in ipa_rx_msg_ccm (asp=0x5f957de3da50, msg=0x5f957de3e750) at ../../src_copy/libosmo-sigtran/src/ipa.c:137 #6 0x000076bb98bac135 in ipa_rx_msg (asp=0x5f957de3da50, msg=0x5f957de3e750, sls=0 '\000') at ../../src_copy/libosmo-sigtran/src/ipa.c:321 #7 0x000076bb98bca44f in ss7_asp_ipa_srv_conn_rx_cb (conn=0x5f957ddba4a0, res=49, msg=0x5f957de3e750) at ../../src_copy/libosmo-sigtran/src/ss7_asp.c:895 #8 0x000076bb988efcb1 in stream_srv_iofd_read_cb (iofd=0x5f957ddd8e40, res=49, msg=0x5f957de3e750) at ../../src_copy/libosmo-netif/src/stream_srv.c:732 #9 0x000076bb98b23c3c in iofd_handle_segmented_read (iofd=0x5f957ddd8e40, msg=0x5f957de3e750, rc=49) at ../../../src_copy/libosmocore/src/core/osmo_io.c:357 #10 0x000076bb98b23d2b in iofd_handle_recv (iofd=0x5f957ddd8e40, msg=0x5f957de3e750, rc=49, hdr=0x0) at ../../../src_copy/libosmocore/src/core/osmo_io.c:384 #11 0x000076bb98b257b7 in iofd_poll_ofd_cb_recvmsg_sendmsg (ofd=0x5f957ddd8ef0, what=1) at ../../../src_copy/libosmocore/src/core/osmo_io_poll.c:64 #12 0x000076bb98b25b32 in iofd_poll_ofd_cb_dispatch (ofd=0x5f957ddd8ef0, what=1) at ../../../src_copy/libosmocore/src/core/osmo_io_poll.c:136 #13 0x000076bb98b2907b in poll_disp_fds (n_fd=6) at ../../../src_copy/libosmocore/src/core/select.c:419 #14 0x000076bb98b29191 in _osmo_select_main (polling=0) at ../../../src_copy/libosmocore/src/core/select.c:457 #15 0x000076bb98b291ac in osmo_select_main (polling=0) at ../../../src_copy/libosmocore/src/core/select.c:496 #16 0x00005f9553dd9a21 in main (argc=3, argv=0x7ffe754fac38) at ../../src_copy/libosmo-sigtran/stp/stp_main.c:270 """ Related: OS#6728 (cherry picked from commit dfccd989dbffe418d9ab7b4d3087345636da762d) Change-Id: I4b893078212444c967164a64219c67f6c6a74c37 --- M src/osmo_ss7_asp.c 1 file changed, 24 insertions(+), 0 deletions(-) git pull ssh://gerrit.osmocom.org:29418/libosmo-sigtran refs/changes/03/40403/1 diff --git a/src/osmo_ss7_asp.c b/src/osmo_ss7_asp.c index 57ebc82..dc60f67 100644 --- a/src/osmo_ss7_asp.c +++ b/src/osmo_ss7_asp.c @@ -802,6 +802,14 @@ int ss7_asp_ipa_srv_conn_rx_cb(struct osmo_stream_srv *conn, int res, struct msgb *msg) { struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn); + struct osmo_stream_srv_link *link = osmo_stream_srv_get_master(conn); + + /* Reparent msg to srv_link, to avoid "msg" being automatically freed if + * "conn" is teared down during msg handling (or if its associated + * dynamic ASP becomes unused), which would then result in a double-free + * if same code path then explicitly frees the msgb through msgb_free(). + */ + talloc_steal(link, msg); if (res <= 0) { if (res == -EAGAIN) { @@ -824,10 +832,18 @@ int ss7_asp_xua_srv_conn_rx_cb(struct osmo_stream_srv *conn, int res, struct msgb *msg) { struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn); + struct osmo_stream_srv_link *link = osmo_stream_srv_get_master(conn); unsigned int ppid; int flags; int rc = 0; + /* Reparent msg to srv_link, to avoid "msg" being automatically freed if + * "conn" is teared down during msg handling (or if its associated + * dynamic ASP becomes unused), which would then result in a double-free + * if same code path then explicitly frees the msgb through msgb_free(). + */ + talloc_steal(link, msg); + /* process the received xUA message */ flags = msgb_sctp_msg_flags(msg); @@ -889,9 +905,17 @@ int ss7_asp_m3ua_tcp_srv_conn_rx_cb(struct osmo_stream_srv *conn, int res, struct msgb *msg) { struct osmo_ss7_asp *asp = osmo_stream_srv_get_data(conn); + struct osmo_stream_srv_link *link = osmo_stream_srv_get_master(conn); const struct xua_common_hdr *hdr; int rc; + /* Reparent msg to srv_link, to avoid "msg" being automatically freed if + * "conn" is teared down during msg handling (or if its associated + * dynamic ASP becomes unused), which would then result in a double-free + * if same code path then explicitly frees the msgb through msgb_free(). + */ + talloc_steal(link, msg); + if (res <= 0) { if (res == -EAGAIN) { msgb_free(msg); -- To view, visit https://gerrit.osmocom.org/c/libosmo-sigtran/+/40403?usp=email To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings?usp=email Gerrit-MessageType: newchange Gerrit-Project: libosmo-sigtran Gerrit-Branch: pespin/rel-2.1.0 Gerrit-Change-Id: I4b893078212444c967164a64219c67f6c6a74c37 Gerrit-Change-Number: 40403 Gerrit-PatchSet: 1 Gerrit-Owner: pespin &lt;pespin(a)sysmocom.de&gt;