From: Dexuan Cui decui@microsoft.com
The patch fixes:
hv_kvp_daemon.c: In function 'kvp_set_ip_info': hv_kvp_daemon.c:1305:2: note: 'snprintf' output between 41 and 4136 bytes into a destination of size 4096
Signed-off-by: Dexuan Cui decui@microsoft.com Cc: K. Y. Srinivasan kys@microsoft.com Cc: Haiyang Zhang haiyangz@microsoft.com Cc: Stephen Hemminger sthemmin@microsoft.com Cc: Stable@vger.kernel.org Signed-off-by: K. Y. Srinivasan kys@microsoft.com --- tools/hv/hv_kvp_daemon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index bbb2a8ef367c..b7c2cf7eaba5 100644 --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -1176,7 +1176,7 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val) int error = 0; char if_file[PATH_MAX]; FILE *file; - char cmd[PATH_MAX]; + char cmd[PATH_MAX * 2]; char *mac_addr;
/*
On Wed, Oct 17, 2018 at 03:14:06AM +0000, kys@linuxonhyperv.com wrote:
From: Dexuan Cui decui@microsoft.com
The patch fixes:
hv_kvp_daemon.c: In function 'kvp_set_ip_info': hv_kvp_daemon.c:1305:2: note: 'snprintf' output between 41 and 4136 bytes into a destination of size 4096
Signed-off-by: Dexuan Cui decui@microsoft.com Cc: K. Y. Srinivasan kys@microsoft.com Cc: Haiyang Zhang haiyangz@microsoft.com Cc: Stephen Hemminger sthemmin@microsoft.com Cc: Stable@vger.kernel.org Signed-off-by: K. Y. Srinivasan kys@microsoft.com
tools/hv/hv_kvp_daemon.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c index bbb2a8ef367c..b7c2cf7eaba5 100644 --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -1176,7 +1176,7 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val) int error = 0; char if_file[PATH_MAX]; FILE *file;
- char cmd[PATH_MAX];
- char cmd[PATH_MAX * 2];
Overkill?
From: devel driverdev-devel-bounces@linuxdriverproject.org On Behalf Of Greg KH Sent: Tuesday, October 16, 2018 22:07
On Wed, Oct 17, 2018 at 03:14:06AM +0000, kys@linuxonhyperv.com wrote:
From: Dexuan Cui decui@microsoft.com
The patch fixes:
hv_kvp_daemon.c: In function 'kvp_set_ip_info': hv_kvp_daemon.c:1305:2: note: 'snprintf' output between 41 and 4136 bytes into a destination of size 4096 ... --- a/tools/hv/hv_kvp_daemon.c +++ b/tools/hv/hv_kvp_daemon.c @@ -1176,7 +1176,7 @@ static int kvp_set_ip_info(char *if_name, struct
hv_kvp_ipaddr_value *new_val)
int error = 0; char if_file[PATH_MAX]; FILE *file;
- char cmd[PATH_MAX];
- char cmd[PATH_MAX * 2];
Overkill?
Well, I found the -Wformat-truncation warning can be suppressed by checking the return value of snprintf, so I'm going to do a new patch for KY to resend like this:
@@ -1178,6 +1178,7 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val) FILE *file; char cmd[PATH_MAX]; char *mac_addr; + int str_len;
/* * Set the configuration for the specified interface with @@ -1301,8 +1302,19 @@ static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val) * invoke the external script to do its magic. */
- snprintf(cmd, sizeof(cmd), KVP_SCRIPTS_PATH "%s %s", - "hv_set_ifconfig", if_file); + str_len = snprintf(cmd, sizeof(cmd), KVP_SCRIPTS_PATH "%s %s", + "hv_set_ifconfig", if_file); + + /* + * This is a little overcautious, but it's necessary to suppress some + * false warnings from gcc 8.0.1. + */ + if (str_len <= 0 || (unsigned int)str_len >= sizeof(cmd)) { + syslog(LOG_ERR, "Cmd '%s' (len=%d) may be too long", + cmd, str_len); + return HV_E_FAIL; + }
Thanks, -- Dexuan
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