diff options
authorNeels Hofmeyr <neels@hofmeyr.de>2019-04-30 02:35:47 +0200
committerHarald Welte <laforge@gnumonks.org>2019-05-05 16:23:41 +0000
commitb3868e14103090ae7d1abb9b84ec217623d8d07a (patch)
parent73c6682f5398eb3457d092b8b5f8ad20a3f5b493 (diff)
gsm48_decode_bcd_number2(): fix input len check
The input_len argument for gsm48_decode_bcd_number2() includes the BCD length *and* the length byte itself, so add the missing +1. Also clarify the API doc for the input_len argument. Change-Id: I87599641325c04aae2be224ec350b1a145039528
1 files changed, 3 insertions, 2 deletions
diff --git a/src/gsm/gsm48_ie.c b/src/gsm/gsm48_ie.c
index 049f5dc6..0e5f2538 100644
--- a/src/gsm/gsm48_ie.c
+++ b/src/gsm/gsm48_ie.c
@@ -80,7 +80,7 @@ int gsm48_decode_bcd_number(char *output, int output_len,
* \param[out] output Caller-provided output buffer.
* \param[in] output_len sizeof(output).
* \param[in] bcd_lv Length-Value part of to-be-decoded IE.
- * \param[in] input_len Size of the buffer to read the IE from.
+ * \param[in] input_len Size of the bcd_lv buffer for bounds checking.
* \param[in] h_len Length of an optional header between L and V parts.
* \return 0 in case of success, negative on error. Errors checked: no or too little input data, no or too little
* output buffer size, IE length exceeds input data size, decoded number exceeds size of the output buffer. The output
@@ -97,7 +97,8 @@ int gsm48_decode_bcd_number2(char *output, size_t output_len,
if (input_len < 1)
return -EIO;
len = bcd_lv[0];
- if (input_len < len)
+ /* len + 1: the BCD length plus the length byte itself must fit in the input buffer. */
+ if (input_len < len + 1)
return -EIO;
return gsm48_decode_bcd_number(output, output_len, bcd_lv, h_len);