mdadm: check value returned by snprintf against errors

GCC 8 checks possible truncation during snprintf more strictly
than GCC 7 which result in compilation errors. To fix this
problem checking result of snprintf against errors has been added.

Signed-off-by: Krzysztof Smolinski <krzysztof.smolinski@intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

diff --git a/sysfs.c b/sysfs.c
index c3137818974ed9eb4c031e5aa4a6f6d36c389cfb..2995713d644d572a447cacdddb1b5b2e043f98a5 100644 (file)
--- a/sysfs.c
+++ b/sysfs.c
@@ -1023,12 +1023,20 @@ int sysfs_rules_apply_check(const struct mdinfo *sra,
        char dname[MAX_SYSFS_PATH_LEN];
        char resolved_path[PATH_MAX];
        char resolved_dir[PATH_MAX];
        char dname[MAX_SYSFS_PATH_LEN];
        char resolved_path[PATH_MAX];
        char resolved_dir[PATH_MAX];

+       int result;

 
        if (sra == NULL || ent == NULL)
                return -1;
 
 
        if (sra == NULL || ent == NULL)
                return -1;
 

-       snprintf(dname, MAX_SYSFS_PATH_LEN, "/sys/block/%s/md/", sra->sys_name);
-       snprintf(fname, MAX_SYSFS_PATH_LEN, "%s/%s", dname, ent->name);
+       result = snprintf(dname, MAX_SYSFS_PATH_LEN,
+                         "/sys/block/%s/md/", sra->sys_name);
+       if (result < 0 || result >= MAX_SYSFS_PATH_LEN)
+               return -1;
+
+       result = snprintf(fname, MAX_SYSFS_PATH_LEN,
+                         "%s/%s", dname, ent->name);
+       if (result < 0 || result >= MAX_SYSFS_PATH_LEN)
+               return -1;

 
        if (realpath(fname, resolved_path) == NULL ||
            realpath(dname, resolved_dir) == NULL)
 
        if (realpath(fname, resolved_path) == NULL ||
            realpath(dname, resolved_dir) == NULL)