fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmo-bts/+/34446?usp=email )

Change subject: l1sap: l1sap_tch_ind(): fix segfault on stale TCH.ind ......................................................................

l1sap: l1sap_tch_ind(): fix segfault on stale TCH.ind

It was reported that osmo-bts-sysmo is crashing due to a TCH.ind primitive being received by l1sap_tch_ind() for an lchan, which is operating neither in speech nor data, but in signalling mode.

It's not clear which scenario is causing this situation. My best guess is that one or more TCH.ind primitive(s) remain waiting in the lower layers and bob up right after the channel mode change.

This can happen, for instance, when a dynamic timeslot gets switched from TCH/F or TCH/H to PDCH or SDCCH/8.

Change-Id: I2d270ab654fdd9d19d1708ff6c4b4e902bd5d0a3 Fixes: d1f8f3429 "l1sap: proper rate adaptation for CSD" Closes: OS#6180 --- M src/common/l1sap.c 1 file changed, 23 insertions(+), 0 deletions(-)

Approvals: osmith: Looks good to me, but someone else must approve fixeria: Looks good to me, approved Jenkins Builder: Verified pespin: Looks good to me, but someone else must approve

diff --git a/src/common/l1sap.c b/src/common/l1sap.c index b828307..844fdad 100644 --- a/src/common/l1sap.c +++ b/src/common/l1sap.c @@ -1990,6 +1990,7 @@ send_ul_rtp_packet_data(lchan, fn, msg->data, msg->len); break; case RSL_CMOD_SPD_SIGN: + return 0; /* drop stale TCH.ind */ default: /* shall not happen */ OSMO_ASSERT(0); }