From 36b604181c1473df79cd8d56f0c01a4f6dce047c Mon Sep 17 00:00:00 2001 From: Neels Hofmeyr Date: Wed, 19 Aug 2020 13:40:33 +0000 Subject: [PATCH] fix crash for unknown MI during Paging Response Related: OS#4724 Related: I40496bbccbbd9c496cfa57df49e26f124a2b1554 (osmo-ttcn3-hacks) Change-Id: Ia2c8fa745cfab17ed7114d433f625ddc02ae7b11 --- src/libmsc/gsm_04_08.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/libmsc/gsm_04_08.c b/src/libmsc/gsm_04_08.c index b284ccd7a..3594bfc79 100644 --- a/src/libmsc/gsm_04_08.c +++ b/src/libmsc/gsm_04_08.c @@ -1185,7 +1185,12 @@ static int gsm48_rx_rr_pag_resp(struct msc_a *msc_a, struct msgb *msg) vsub = msc_a_vsub(msc_a); if (!vsub) { LOG_MSC_A(msc_a, LOGL_ERROR, "subscriber not allowed to do a Paging Response\n"); - msc_a_put(msc_a, MSC_A_USE_PAGING_RESPONSE); + + /* Above MSC_A_USE_PAGING_RESPONSE may already have been removed by a forced release, put that use only + * if it still exists. (see msc_a_fsm_releasing_onenter()) */ + if (osmo_use_count_by(&msc_a->use_count, MSC_A_USE_PAGING_RESPONSE)) + msc_a_put(msc_a, MSC_A_USE_PAGING_RESPONSE); + return -EIO; }