libkmod: treat read_long failures

If read_long fails, forward error up to caller. Also perform proper
fread return value check.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/123
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>

diff --git a/libkmod/libkmod-index.c b/libkmod/libkmod-index.c
index d738ea871d3f2a22ed4f2c1b27702e9690854123..f6409868d18e0eb5ee2f5fb279fd4b9bb9e61f37 100644 (file)
--- a/libkmod/libkmod-index.c
+++ b/libkmod/libkmod-index.c
@@ -183,14 +183,17 @@ static int read_char(FILE *in)
        return ch;
 }
 
-static uint32_t read_long(FILE *in)
+static int read_long(FILE *in, uint32_t *l)
 {
-       uint32_t l;
+       uint32_t val;
 
        errno = 0;
-       if (fread(&l, sizeof(uint32_t), 1, in) != sizeof(uint32_t))
+       if (fread(&val, sizeof(uint32_t), 1, in) != 1) {
                read_error();
-       return ntohl(l);
+               return -1;
+       }
+       *l = ntohl(val);
+       return 1;
 }
 
 static ssize_t buf_freadchars(struct strbuf *buf, FILE *in)
@@ -254,7 +257,8 @@ static struct index_node_f *index_read(FILE *in, uint32_t offset)
                node->last = last;
 
                for (i = 0; i < child_count; i++)
-                       node->children[i] = read_long(in);
+                       if (read_long(in, &node->children[i]) < 0)
+                               goto err;
        } else {
                node = NOFAIL(malloc(sizeof(struct index_node_f)));
                node->first = INDEX_CHILDMAX;
@@ -263,17 +267,18 @@ static struct index_node_f *index_read(FILE *in, uint32_t offset)
 
        node->values = NULL;
        if (offset & INDEX_NODE_VALUES) {
-               int value_count;
+               uint32_t value_count;
                struct strbuf buf;
                const char *value;
                unsigned int priority;
 
-               value_count = read_long(in);
+               if (read_long(in, &value_count) < 0)
+                       goto err;
 
                strbuf_init(&buf);
                while (value_count--) {
-                       priority = read_long(in);
-                       if (buf_freadchars(&buf, in) < 0) {
+                       if (read_long(in, &priority) < 0 ||
+                           buf_freadchars(&buf, in) < 0) {
                                strbuf_release(&buf);
                                goto err;
                        }
@@ -316,24 +321,23 @@ struct index_file *index_file_open(const char *filename)
                return NULL;
        errno = EINVAL;
 
-       magic = read_long(file);
-       if (magic != INDEX_MAGIC) {
-               fclose(file);
-               return NULL;
-       }
+       if (read_long(file, &magic) < 0 || magic != INDEX_MAGIC)
+               goto err;
 
-       version = read_long(file);
-       if (version >> 16 != INDEX_VERSION_MAJOR) {
-               fclose(file);
-               return NULL;
-       }
+       if (read_long(file, &version) < 0 ||
+           version >> 16 != INDEX_VERSION_MAJOR)
+               goto err;
 
        new = NOFAIL(malloc(sizeof(struct index_file)));
        new->file = file;
-       new->root_offset = read_long(new->file);
+       if (read_long(new->file, &new->root_offset) < 0)
+               goto err;
 
        errno = 0;
        return new;
+err:
+       fclose(file);
+       return NULL;
 }
 
 void index_file_close(struct index_file *idx)