From 4183ec3a135663128834ca8b35d50a60999343a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
Date: Fri, 7 Dec 2018 10:48:10 +0100
Subject: [PATCH] journal-remote: set a limit on the number of fields in a
 message

Existing use of E2BIG is replaced with ENOBUFS (entry too long), and E2BIG is
reused for the new error condition (too many fields).

This matches the change done for systemd-journald, hence forming the second
part of the fix for CVE-2018-16865
(https://bugzilla.redhat.com/show_bug.cgi?id=1653861).

Patch backported from systemd master at
ef4d6abe7c7fab6cbff975b32e76b09feee56074.
---
 src/basic/journal-importer.c             |  5 ++++-
 src/journal-remote/journal-remote-main.c | 10 ++++++----
 src/journal-remote/journal-remote.c      |  5 ++++-
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/basic/journal-importer.c b/src/basic/journal-importer.c
index ca203bbbfc..3ac55a66d9 100644
--- a/src/basic/journal-importer.c
+++ b/src/basic/journal-importer.c
@@ -23,6 +23,9 @@ enum {
 };
 
 static int iovw_put(struct iovec_wrapper *iovw, void* data, size_t len) {
+        if (iovw->count >= ENTRY_FIELD_COUNT_MAX)
+                return -E2BIG;
+
         if (!GREEDY_REALLOC(iovw->iovec, iovw->size_bytes, iovw->count + 1))
                 return log_oom();
 
@@ -98,7 +101,7 @@ static int get_line(JournalImporter *imp, char **line, size_t *size) {
                 imp->scanned = imp->filled;
                 if (imp->scanned >= DATA_SIZE_MAX) {
                         log_error("Entry is bigger than %u bytes.", DATA_SIZE_MAX);
-                        return -E2BIG;
+                        return -ENOBUFS;
                 }
 
                 if (imp->passive_fd)
diff --git a/src/journal-remote/journal-remote-main.c b/src/journal-remote/journal-remote-main.c
index 8fda9d1499..f52618fb7b 100644
--- a/src/journal-remote/journal-remote-main.c
+++ b/src/journal-remote/journal-remote-main.c
@@ -212,10 +212,12 @@ static int process_http_upload(
                         break;
                 else if (r < 0) {
                         log_warning("Failed to process data for connection %p", connection);
-                        if (r == -E2BIG)
-                                return mhd_respondf(connection,
-                                                    r, MHD_HTTP_PAYLOAD_TOO_LARGE,
-                                                    "Entry is too large, maximum is " STRINGIFY(DATA_SIZE_MAX) " bytes.");
+                        if (r == -ENOBUFS)
+                                log_warning_errno(r, "Entry is above the maximum of %u, aborting connection %p.",
+                                                  DATA_SIZE_MAX, connection);
+                        else if (r == -E2BIG)
+                                log_warning_errno(r, "Entry with more fields than the maximum of %u, aborting connection %p.",
+                                                  ENTRY_FIELD_COUNT_MAX, connection);
                         else
                                 return mhd_respondf(connection,
                                                     r, MHD_HTTP_UNPROCESSABLE_ENTITY,
diff --git a/src/journal-remote/journal-remote.c b/src/journal-remote/journal-remote.c
index beb75a1cb4..67e3a70c06 100644
--- a/src/journal-remote/journal-remote.c
+++ b/src/journal-remote/journal-remote.c
@@ -408,7 +408,10 @@ int journal_remote_handle_raw_source(
                 log_debug("%zu active sources remaining", s->active);
                 return 0;
         } else if (r == -E2BIG) {
-                log_notice_errno(E2BIG, "Entry too big, skipped");
+                log_notice("Entry with too many fields, skipped");
+                return 1;
+        } else if (r == -ENOBUFS) {
+                log_notice("Entry too big, skipped");
                 return 1;
         } else if (r == -EAGAIN) {
                 return 0;
-- 
2.11.0