color: protect against out-of-bounds reads and writes

diff --git a/log-tree.c b/log-tree.c
index 66329d089d8521b8335cfc373f127b16c4f860ed..4aef85331e0b696d0373cf1bdb0743a7e6b58c36 100644 (file)
--- a/log-tree.c
+++ b/log-tree.c
@@ -362,7 +362,8 @@ void fmt_output_email_subject(struct strbuf *sb, struct rev_info *opt)
 
 void log_write_email_headers(struct rev_info *opt, struct commit *commit,
                             const char **extra_headers_p,
-                            int *need_8bit_cte_p)
+                            int *need_8bit_cte_p,
+                            int maybe_multipart)
 {
        const char *extra_headers = opt->extra_headers;
        const char *name = oid_to_hex(opt->zero_commit ?
@@ -385,12 +386,16 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
                               opt->ref_message_ids->items[i].string);
                graph_show_oneline(opt->graph);
        }
-       if (opt->mime_boundary) {
-               static char subject_buffer[1024];
-               static char buffer[1024];
+       if (opt->mime_boundary && maybe_multipart) {
+               static struct strbuf subject_buffer = STRBUF_INIT;
+               static struct strbuf buffer = STRBUF_INIT;
                struct strbuf filename =  STRBUF_INIT;
                *need_8bit_cte_p = -1; /* NEVER */
-               snprintf(subject_buffer, sizeof(subject_buffer) - 1,
+
+               strbuf_reset(&subject_buffer);
+               strbuf_reset(&buffer);
+
+               strbuf_addf(&subject_buffer,
                         "%s"
                         "MIME-Version: 1.0\n"
                         "Content-Type: multipart/mixed;"
@@ -405,13 +410,13 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
                         extra_headers ? extra_headers : "",
                         mime_boundary_leader, opt->mime_boundary,
                         mime_boundary_leader, opt->mime_boundary);
-               extra_headers = subject_buffer;
+               extra_headers = subject_buffer.buf;
 
                if (opt->numbered_files)
                        strbuf_addf(&filename, "%d", opt->nr);
                else
                        fmt_output_commit(&filename, commit, opt);
-               snprintf(buffer, sizeof(buffer) - 1,
+               strbuf_addf(&buffer,
                         "\n--%s%s\n"
                         "Content-Type: text/x-patch;"
                         " name=\"%s\"\n"
@@ -422,7 +427,7 @@ void log_write_email_headers(struct rev_info *opt, struct commit *commit,
                         filename.buf,
                         opt->no_inline ? "attachment" : "inline",
                         filename.buf);
-               opt->diffopt.stat_sep = buffer;
+               opt->diffopt.stat_sep = buffer.buf;
                strbuf_release(&filename);
        }
        *extra_headers_p = extra_headers;
@@ -611,7 +616,7 @@ void show_log(struct rev_info *opt)
 
        if (cmit_fmt_is_mail(opt->commit_format)) {
                log_write_email_headers(opt, commit, &extra_headers,
-                                       &ctx.need_8bit_cte);
+                                       &ctx.need_8bit_cte, 1);
                ctx.rev = opt;
                ctx.print_email_subject = 1;
        } else if (opt->commit_format != CMIT_FMT_USERFORMAT) {