From 97248e26cdd728c025cc709496d4250350a4878a Mon Sep 17 00:00:00 2001

From: Yi EungJun <semtlenori@gmail.com>

Date: Sun, 7 Aug 2016 05:39:13 +0900

Subject: [PATCH] journal-gatewayd: fix segfault with certain request (#3893)

When client requests to get logs with `follow` and `KEY=match` that

doesn't match any log entry, journal-gatewayd segfaulted.

Make request_reader_entries to return zero in such case to wait for

matching entries.

This fixes https://github.com/systemd/systemd/issues/3873.

(cherry picked from commit 3475fc5899db8c8c9198573912429b85213e4862)

---

 src/journal-remote/journal-gatewayd.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/src/journal-remote/journal-gatewayd.c b/src/journal-remote/journal-gatewayd.c

index 4ad9184993..e4a82871b5 100644

--- a/src/journal-remote/journal-gatewayd.c

+++ b/src/journal-remote/journal-gatewayd.c

@@ -239,6 +239,9 @@ static ssize_t request_reader_entries(

                 m->size = (uint64_t) sz;

         }

+        if (m->tmp == NULL && m->follow)

+                return 0;

+

         if (fseeko(m->tmp, pos, SEEK_SET) < 0) {

                 log_error_errno(errno, "Failed to seek to position: %m");

                 return MHD_CONTENT_READER_END_WITH_ERROR;