From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:41530 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728339AbgCKJJS (ORCPT ); Wed, 11 Mar 2020 05:09:18 -0400 From: Takashi Iwai Subject: [PATCH] s390/zcrypt: Use scnprintf() for avoiding potential buffer overflow Date: Wed, 11 Mar 2020 10:09:15 +0100 Message-Id: <20200311090915.21059-1-tiwai@suse.de> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Harald Freudenberger Cc: Heiko Carstens , Vasily Gorbik , Christian Borntraeger , linux-s390@vger.kernel.org Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Signed-off-by: Takashi Iwai --- drivers/s390/crypto/zcrypt_cex4.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/s390/crypto/zcrypt_cex4.c b/drivers/s390/crypto/zcrypt_cex4.c index 9a9d02e19774..dea96d5b65fb 100644 --- a/drivers/s390/crypto/zcrypt_cex4.c +++ b/drivers/s390/crypto/zcrypt_cex4.c @@ -128,16 +128,16 @@ static ssize_t cca_mkvps_show(struct device *dev, n = snprintf(buf, PAGE_SIZE, "AES NEW: - -\n"); if (ci.cur_mk_state >= '1' && ci.cur_mk_state <= '2') - n += snprintf(buf + n, PAGE_SIZE - n, "AES CUR: %s 0x%016llx\n", + n += scnprintf(buf + n, PAGE_SIZE - n, "AES CUR: %s 0x%016llx\n", cao_state[ci.cur_mk_state - '1'], ci.cur_mkvp); else - n += snprintf(buf + n, PAGE_SIZE - n, "AES CUR: - -\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "AES CUR: - -\n"); if (ci.old_mk_state >= '1' && ci.old_mk_state <= '2') - n += snprintf(buf + n, PAGE_SIZE - n, "AES OLD: %s 0x%016llx\n", + n += scnprintf(buf + n, PAGE_SIZE - n, "AES OLD: %s 0x%016llx\n", cao_state[ci.old_mk_state - '1'], ci.old_mkvp); else - n += snprintf(buf + n, PAGE_SIZE - n, "AES OLD: - -\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "AES OLD: - -\n"); return n; } @@ -251,11 +251,11 @@ static ssize_t ep11_card_op_modes_show(struct device *dev, if (ci.op_mode & (1 << ep11_op_modes[i].mode_bit)) { if (n > 0) buf[n++] = ' '; - n += snprintf(buf + n, PAGE_SIZE - n, + n += scnprintf(buf + n, PAGE_SIZE - n, "%s", ep11_op_modes[i].mode_txt); } } - n += snprintf(buf + n, PAGE_SIZE - n, "\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "\n"); return n; } @@ -305,21 +305,21 @@ static ssize_t ep11_mkvps_show(struct device *dev, cwk_state[di.cur_wk_state - '0']); bin2hex(buf + n, di.cur_wkvp, sizeof(di.cur_wkvp)); n += 2 * sizeof(di.cur_wkvp); - n += snprintf(buf + n, PAGE_SIZE - n, "\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "\n"); } else n = snprintf(buf, PAGE_SIZE, "WK CUR: - -\n"); if (di.new_wk_state == '0') { - n += snprintf(buf + n, PAGE_SIZE - n, "WK NEW: %s -\n", + n += scnprintf(buf + n, PAGE_SIZE - n, "WK NEW: %s -\n", nwk_state[di.new_wk_state - '0']); } else if (di.new_wk_state >= '1' && di.new_wk_state <= '2') { - n += snprintf(buf + n, PAGE_SIZE - n, "WK NEW: %s 0x", + n += scnprintf(buf + n, PAGE_SIZE - n, "WK NEW: %s 0x", nwk_state[di.new_wk_state - '0']); bin2hex(buf + n, di.new_wkvp, sizeof(di.new_wkvp)); n += 2 * sizeof(di.new_wkvp); - n += snprintf(buf + n, PAGE_SIZE - n, "\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "\n"); } else - n += snprintf(buf + n, PAGE_SIZE - n, "WK NEW: - -\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "WK NEW: - -\n"); return n; } @@ -346,11 +346,11 @@ static ssize_t ep11_queue_op_modes_show(struct device *dev, if (di.op_mode & (1 << ep11_op_modes[i].mode_bit)) { if (n > 0) buf[n++] = ' '; - n += snprintf(buf + n, PAGE_SIZE - n, + n += scnprintf(buf + n, PAGE_SIZE - n, "%s", ep11_op_modes[i].mode_txt); } } - n += snprintf(buf + n, PAGE_SIZE - n, "\n"); + n += scnprintf(buf + n, PAGE_SIZE - n, "\n"); return n; } -- 2.16.4