[PATCH 7/8] msgb: Assert len >= 0 in msgb_trim

[Jacob Erlbeck]

Currently msgb_trim only checks for len > data_len and returns -1
in that case, allowing the caller to fix it somehow. Using a negative
length will always lead to a corrupt msgb, but this is not being
checked.

This commit adds a check for len < 0 and a conditional call to MSGB_ABORT.

Sponsored-by: On-Waves ehf
---
 include/osmocom/core/msgb.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/osmocom/core/msgb.h b/include/osmocom/core/msgb.h
index 9c99cad..b057caa 100644
--- a/include/osmocom/core/msgb.h
+++ b/include/osmocom/core/msgb.h
@@ -373,6 +373,8 @@ static inline void msgb_reserve(struct msgb *msg, int len)
  */
 static inline int msgb_trim(struct msgb *msg, int len)
 {
+	if (len < 0)
+		MSGB_ABORT(msg, "Negative length is not allowed\n");
 	if (len > msg->data_len)
 		return -1;
 
-- 
1.9.1