forked from pool/s390-tools
70 lines
2.5 KiB
Diff
70 lines
2.5 KiB
Diff
|
From 1261105fe238ad306db29a9d47bb1a293bddf9aa Mon Sep 17 00:00:00 2001
|
||
|
|
From: =?UTF-8?q?Jan=20H=C3=B6ppner?= <hoeppner@linux.vnet.ibm.com>
|
||
|
|
Date: Mon, 16 Oct 2017 15:46:07 +0200
|
||
|
|
Subject: [PATCH] dasdinfo: Fix truncation warning
|
||
|
|
MIME-Version: 1.0
|
||
|
|
Content-Type: text/plain; charset=UTF-8
|
||
|
|
Content-Transfer-Encoding: 8bit
|
||
|
|
|
||
|
|
Commit 3c80f7e025db ("dasdinfo: fix buffer overflow warning") changed a
|
||
|
|
sprintf call to snprintf to avoid a buffer overflow warning. However,
|
||
|
|
GCC 7 now warns about a potential truncation with snprintf:
|
||
|
|
|
||
|
|
dasdinfo.c: In function 'main':
|
||
|
|
dasdinfo.c:577:18: warning: '%s' directive output may be truncated
|
||
|
|
writing up to 255 bytes into a region of size 69 [-Wformat-truncation=]
|
||
|
|
"/sys/block/%s/device/uid", dir_entry->d_name);
|
||
|
|
^~
|
||
|
|
dasdinfo.c:576:4: note: 'snprintf' output between 23 and 278 bytes into
|
||
|
|
a destination of size 80
|
||
|
|
snprintf(*uidfile, RD_BUFFER_SIZE,
|
||
|
|
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
"/sys/block/%s/device/uid", dir_entry->d_name);
|
||
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||
|
|
|
||
|
|
We could get around this by increasing the buffer. Though, the current
|
||
|
|
buffer size is already plenty and we know better anyway.
|
||
|
|
Avoid the warning by simply checking the return value of snprintf and
|
||
|
|
display an error in case data was truncated nonetheless.
|
||
|
|
|
||
|
|
Fixes: 3c80f7e025db ("dasdinfo: fix buffer overflow warning")
|
||
|
|
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
|
||
|
|
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
|
||
|
|
---
|
||
|
|
dasdinfo/dasdinfo.c | 12 ++++++++++--
|
||
|
|
1 file changed, 10 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/dasdinfo/dasdinfo.c b/dasdinfo/dasdinfo.c
|
||
|
|
index c8bda3b..f881f03 100644
|
||
|
|
--- a/dasdinfo/dasdinfo.c
|
||
|
|
+++ b/dasdinfo/dasdinfo.c
|
||
|
|
@@ -545,6 +545,7 @@ static int dinfo_get_uid_from_devnode(char **uidfile, char *devnode)
|
||
|
|
char *readbuf;
|
||
|
|
DIR *directory = NULL;
|
||
|
|
struct dirent *dir_entry = NULL;
|
||
|
|
+ int rc = 0;
|
||
|
|
|
||
|
|
if (stat(devnode, &stat_buffer) != 0) {
|
||
|
|
printf("Error: could not stat %s\n", devnode);
|
||
|
|
@@ -573,8 +574,15 @@ static int dinfo_get_uid_from_devnode(char **uidfile, char *devnode)
|
||
|
|
|
||
|
|
if (strncmp(stat_dev, readbuf,
|
||
|
|
MAX(strlen(stat_dev), strlen(readbuf)-1)) == 0) {
|
||
|
|
- snprintf(*uidfile, RD_BUFFER_SIZE,
|
||
|
|
- "/sys/block/%s/device/uid", dir_entry->d_name);
|
||
|
|
+ rc = snprintf(*uidfile, RD_BUFFER_SIZE,
|
||
|
|
+ "/sys/block/%s/device/uid",
|
||
|
|
+ dir_entry->d_name);
|
||
|
|
+ if (rc >= RD_BUFFER_SIZE) {
|
||
|
|
+ fprintf(stderr,
|
||
|
|
+ "Error: Device name was truncated\n");
|
||
|
|
+ return -1;
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
--
|
||
|
|
1.7.12.4
|
||
|
|
|