diff options
Diffstat (limited to 'util.c')
| -rw-r--r-- | util.c | 15 |
1 files changed, 12 insertions, 3 deletions
@@ -90,16 +90,16 @@ int checksum(const u8 *buf, size_t len) /* * Reads all of file from given offset, up to max_len bytes. - * A buffer of max_len bytes is allocated by this function, and + * A buffer of at most max_len bytes is allocated by this function, and * needs to be freed by the caller. * This provides a similar usage model to mem_chunk() * - * Returns pointer to buffer of max_len bytes, or NULL on error, and + * Returns a pointer to the allocated buffer, or NULL on error, and * sets max_len to the length actually read. - * */ void *read_file(off_t base, size_t *max_len, const char *filename) { + struct stat statbuf; int fd; size_t r2 = 0; ssize_t r; @@ -124,6 +124,15 @@ void *read_file(off_t base, size_t *max_len, const char *filename) goto out; } + /* + * Check file size, don't allocate more than can be read. + */ + if (fstat(fd, &statbuf) == 0) + { + if (base + (off_t)*max_len > statbuf.st_size) + *max_len = statbuf.st_size - base; + } + if ((p = malloc(*max_len)) == NULL) { perror("malloc"); |