systemd: Security fix CVE-2018-16865

Affects < v240

Based on thud commit d5d2b821fc85b8cf39f683061ac2a45bddd2139f
The second patch in the thud commit doesn't apply against 237. Use the
version of the second patch CVE-2018-16865_2.patch from
systemd_237-3ubuntu10.13.debian.

(From OE-Core rev: da41e48567eb21a47426a6fbe23ea07ce780cd3c)

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

3 files changed, 141 insertions, 0 deletions

diff --git a/meta/recipes-core/systemd/systemd/0025-journald-set-a-limit-on-the-number-of-fields-1k.patch b/meta/recipes-core/systemd/systemd/0025-journald-set-a-limit-on-the-number-of-fields-1k.patch
new file mode 100644
index 0000000000..e8a6f2b986
--- /dev/null
+++ b/meta/recipes-core/systemd/systemd/0025-journald-set-a-limit-on-the-number-of-fields-1k.patch
@@ -0,0 +1,60 @@
+From 4566aaf97f5b4143b930d75628f3abc905249dcd Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= <zbyszek@in.waw.pl>
+Date: Wed, 5 Dec 2018 22:45:02 +0100
+Subject: [PATCH] journald: set a limit on the number of fields (1k)
+
+We allocate a iovec entry for each field, so with many short entries,
+our memory usage and processing time can be large, even with a relatively
+small message size. Let's refuse overly long entries.
+
+CVE-2018-16865
+https://bugzilla.redhat.com/show_bug.cgi?id=1653861
+
+What from I can see, the problem is not from an alloca, despite what the CVE
+description says, but from the attack multiplication that comes from creating
+many very small iovecs: (void* + size_t) for each three bytes of input message.
+
+Patch backported from systemd master at
+052c57f132f04a3cf4148f87561618da1a6908b4.
+
+CVE: CVE-2018-16865
+Upstream-Status: Backport
+
+---
+ src/basic/journal-importer.h  | 3 +++
+ src/journal/journald-native.c | 5 +++++
+ 2 files changed, 8 insertions(+)
+
+diff --git a/src/basic/journal-importer.h b/src/basic/journal-importer.h
+index f49ce734a1..c4ae45d32d 100644
+--- a/src/basic/journal-importer.h
++++ b/src/basic/journal-importer.h
+@@ -16,6 +16,9 @@
+ #define DATA_SIZE_MAX (1024*1024*768u)
+ #define LINE_CHUNK 8*1024u
+ 
++/* The maximum number of fields in an entry */
++#define ENTRY_FIELD_COUNT_MAX 1024
++
+ struct iovec_wrapper {
+         struct iovec *iovec;
+         size_t size_bytes;
+diff --git a/src/journal/journald-native.c b/src/journal/journald-native.c
+index 5ff22a10af..951d092053 100644
+--- a/src/journal/journald-native.c
++++ b/src/journal/journald-native.c
+@@ -140,6 +140,11 @@ static int server_process_entry(
+                 }
+ 
+                 /* A property follows */
++                if (n > ENTRY_FIELD_COUNT_MAX) {
++                        log_debug("Received an entry that has more than " STRINGIFY(ENTRY_FIELD_COUNT_MAX) " fields, ignoring entry.");
++                        r = 1;
++                        goto finish;
++                }
+ 
+                 /* n existing properties, 1 new, +1 for _TRANSPORT */
+                 if (!GREEDY_REALLOC(iovec, m,
+-- 
+2.11.0
+
diff --git a/meta/recipes-core/systemd/systemd/0026-journal-remote-set-a-limit-on-the-number-of-fields-i.patch b/meta/recipes-core/systemd/systemd/0026-journal-remote-set-a-limit-on-the-number-of-fields-i.patch
new file mode 100644
index 0000000000..f297333e72
--- /dev/null
+++ b/meta/recipes-core/systemd/systemd/0026-journal-remote-set-a-limit-on-the-number-of-fields-i.patch
@@ -0,0 +1,79 @@
+From ce1475b4f69f0a4382c6190f55e080d91de84611 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.
+
+Patch for 237 from:
+systemd_237-3ubuntu10.13.debian CVE-2018-16865_2.patch
+
+CVE: CVE-2018-16865
+Upstream-Status: Backport
+
+---
+ src/journal-remote/journal-remote-main.c | 7 +++++--
+ src/journal-remote/journal-remote.c      | 3 +++
+ src/shared/journal-importer.c            | 5 ++++-
+ 3 files changed, 12 insertions(+), 3 deletions(-)
+
+--- a/src/basic/journal-importer.c
++++ b/src/basic/journal-importer.c
+@@ -38,6 +38,9 @@
+ };
+ 
+ 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();
+ 
+@@ -113,7 +116,7 @@
+                 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)
+--- a/src/journal-remote/journal-remote.c
++++ b/src/journal-remote/journal-remote.c
+@@ -517,10 +517,16 @@
+                         break;
+                 else if (r < 0) {
+                         log_warning("Failed to process data for connection %p", connection);
+-                        if (r == -E2BIG)
++                        if (r == -ENOBUFS)
+                                 return mhd_respondf(connection,
+                                                     r, MHD_HTTP_PAYLOAD_TOO_LARGE,
+                                                     "Entry is too large, maximum is " STRINGIFY(DATA_SIZE_MAX) " bytes.");
++
++                        else if (r == -E2BIG)
++                                return mhd_respondf(connection,
++                                                    r, MHD_HTTP_REQUEST_ENTITY_TOO_LARGE,
++                                                    "Entry with more fields than the maximum of " STRINGIFY(ENTRY_FIELD_COUNT_MAX) ".");
++
+                         else
+                                 return mhd_respondf(connection,
+                                                     r, MHD_HTTP_UNPROCESSABLE_ENTITY,
+@@ -1090,6 +1096,9 @@
+                 log_debug("%zu active sources remaining", s->active);
+                 return 0;
+         } else if (r == -E2BIG) {
++                log_notice("Entry with too many fields, skipped");
++                return 1;
++        } else if (r == -ENOBUFS) {
+                 log_notice_errno(E2BIG, "Entry too big, skipped");
+                 return 1;
+         } else if (r == -EAGAIN) {
diff --git a/meta/recipes-core/systemd/systemd_237.bb b/meta/recipes-core/systemd/systemd_237.bb
index 61d25e5135..fd110a8340 100644
--- a/meta/recipes-core/systemd/systemd_237.bb
+++ b/meta/recipes-core/systemd/systemd_237.bb
@@ -58,6 +58,8 @@ SRC_URI += "file://touchscreen.rules \
            file://0001-chown-recursive-let-s-rework-the-recursive-logic-to-.patch \
            file://0001-dhcp6-make-sure-we-have-enough-space-for-the-DHCP6-o.patch \
            file://0024-journald-do-not-store-the-iovec-entry-for-process-co.patch \
+           file://0025-journald-set-a-limit-on-the-number-of-fields-1k.patch \
+           file://0026-journal-remote-set-a-limit-on-the-number-of-fields-i.patch \
            "
 SRC_URI_append_qemuall = " file://0001-core-device.c-Change-the-default-device-timeout-to-2.patch"