From: Florian Fainelli f.fainelli@gmail.com
[ Upstream commit 6c58cf40e3a1d2f47c09d3489857e9476316788a ]
A build with -D_FORTIFY_SOURCE=2 enabled will produce the following warnings:
sysfs.c:63:30: warning: '%s' directive output may be truncated writing up to 255 bytes into a region of size between 0 and 255 [-Wformat-truncation=] snprintf(filepath, 256, "%s/%s", path, filename); ^~ Bump up the buffer to PATH_MAX which is the limit and account for all of the possible NUL and separators that could lead to exceeding the allocated buffer sizes.
Fixes: 94f69966faf8 ("tools/thermal: Introduce tmon, a tool for thermal subsystem") Signed-off-by: Florian Fainelli f.fainelli@gmail.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/thermal/tmon/sysfs.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/tools/thermal/tmon/sysfs.c b/tools/thermal/tmon/sysfs.c index 18f523557983..1b17cbc54c9d 100644 --- a/tools/thermal/tmon/sysfs.c +++ b/tools/thermal/tmon/sysfs.c @@ -22,6 +22,7 @@ #include <stdint.h> #include <dirent.h> #include <libintl.h> +#include <limits.h> #include <ctype.h> #include <time.h> #include <syslog.h> @@ -42,9 +43,9 @@ int sysfs_set_ulong(char *path, char *filename, unsigned long val) { FILE *fd; int ret = -1; - char filepath[256]; + char filepath[PATH_MAX + 2]; /* NUL and '/' */
- snprintf(filepath, 256, "%s/%s", path, filename); + snprintf(filepath, sizeof(filepath), "%s/%s", path, filename);
fd = fopen(filepath, "w"); if (!fd) { @@ -66,9 +67,9 @@ static int sysfs_get_ulong(char *path, char *filename, unsigned long *p_ulong) { FILE *fd; int ret = -1; - char filepath[256]; + char filepath[PATH_MAX + 2]; /* NUL and '/' */
- snprintf(filepath, 256, "%s/%s", path, filename); + snprintf(filepath, sizeof(filepath), "%s/%s", path, filename);
fd = fopen(filepath, "r"); if (!fd) { @@ -85,9 +86,9 @@ static int sysfs_get_string(char *path, char *filename, char *str) { FILE *fd; int ret = -1; - char filepath[256]; + char filepath[PATH_MAX + 2]; /* NUL and '/' */
- snprintf(filepath, 256, "%s/%s", path, filename); + snprintf(filepath, sizeof(filepath), "%s/%s", path, filename);
fd = fopen(filepath, "r"); if (!fd) { @@ -208,8 +209,8 @@ static int find_tzone_cdev(struct dirent *nl, char *tz_name, { unsigned long trip_instance = 0; char cdev_name_linked[256]; - char cdev_name[256]; - char cdev_trip_name[256]; + char cdev_name[PATH_MAX]; + char cdev_trip_name[PATH_MAX]; int cdev_id;
if (nl->d_type == DT_LNK) { @@ -222,7 +223,8 @@ static int find_tzone_cdev(struct dirent *nl, char *tz_name, return -EINVAL; } /* find the link to real cooling device record binding */ - snprintf(cdev_name, 256, "%s/%s", tz_name, nl->d_name); + snprintf(cdev_name, sizeof(cdev_name) - 2, "%s/%s", + tz_name, nl->d_name); memset(cdev_name_linked, 0, sizeof(cdev_name_linked)); if (readlink(cdev_name, cdev_name_linked, sizeof(cdev_name_linked) - 1) != -1) { @@ -235,8 +237,8 @@ static int find_tzone_cdev(struct dirent *nl, char *tz_name, /* find the trip point in which the cdev is binded to * in this tzone */ - snprintf(cdev_trip_name, 256, "%s%s", nl->d_name, - "_trip_point"); + snprintf(cdev_trip_name, sizeof(cdev_trip_name) - 1, + "%s%s", nl->d_name, "_trip_point"); sysfs_get_ulong(tz_name, cdev_trip_name, &trip_instance); /* validate trip point range, e.g. trip could return -1