soc: qcom: qmi_encdec: Restrict string length in decode

The QMI TLV value for strings in a lot of qmi element info structures
account for null terminated strings with MAX_LEN + 1. If a string is
actually MAX_LEN + 1 length, this will cause an out of bounds access
when the NULL character is appended in decoding.

CR-Fixed: 2359244
Change-Id: I4d789bc6017ff58458f77fe875ca4e175a4f1357
Signed-off-by: Chris Lew <clew@codeaurora.org>
Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
This commit is contained in:
Deepak Kumar Singh 2019-03-05 17:16:54 +05:30 committed by Gerrit - the friendly Code Review server
parent a1b80321ae
commit 4fedfe5c4d

View file

@ -1,4 +1,4 @@
/* Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
/* Copyright (c) 2012-2015, 2019 The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@ -710,8 +710,8 @@ static int qmi_decode_string_elem(struct elem_info *ei_array, void *buf_dst,
decoded_bytes += rc;
}
if (string_len > temp_ei->elem_len) {
pr_err("%s: String len %d > Max Len %d\n",
if (string_len >= temp_ei->elem_len) {
pr_err("%s: String len %d >= Max Len %d\n",
__func__, string_len, temp_ei->elem_len);
return -ETOOSMALL;
} else if (string_len > tlv_len) {