commit d9d62102cc41533a5062d29f4abd4b272d71840f
author Philipp Maier <pmaier@sysmocom.de> Tue Oct 04 14:43:25 2022 +0200
committer laforge <laforge@osmocom.org> Thu Oct 06 07:52:09 2022 +0000
tree f0222b8431c9ac52d093cdc94b002cc901929283
parent 486d98404d3e035029c18105580229784a457745

msgb: assert msgb->lXh to be not NULL

When any of l1h, l2h, l2h or l4h is set to NULL (which is the default
for newly allocated message buffers). Then the msgb_lXhlen() functions
will return the address value of msgb->tail. This can lead to unexpected
results at a later point. We should have an OSMO_ASSERT to catch the
problem early.

Change-Id: I1795c559f190713ebbabfbabf3453ab77da46a49
Related: OS#5645

include/osmocom/core/msgb.h

diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 117fcb0..fbf1742 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -144,6 +144,7 @@
  */
 static inline unsigned int msgb_l1len(const struct msgb *msgb)
 {
+	OSMO_ASSERT(msgb->l1h);
 	return msgb->tail - (uint8_t *)msgb_l1(msgb);
 }
 
@@ -156,6 +157,7 @@
  */
 static inline unsigned int msgb_l2len(const struct msgb *msgb)
 {
+	OSMO_ASSERT(msgb->l2h);
 	return msgb->tail - (uint8_t *)msgb_l2(msgb);
 }
 
@@ -168,6 +170,7 @@
  */
 static inline unsigned int msgb_l3len(const struct msgb *msgb)
 {
+	OSMO_ASSERT(msgb->l3h);
 	return msgb->tail - (uint8_t *)msgb_l3(msgb);
 }
 
@@ -180,6 +183,7 @@
  */
 static inline unsigned int msgb_l4len(const struct msgb *msgb)
 {
+	OSMO_ASSERT(msgb->l4h);
 	return msgb->tail - (uint8_t *)msgb_sms(msgb);
 }