postgresql: fix CVE-2021-23214,CVE-2021-23222

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

3 files changed, 249 insertions, 0 deletions

diff --git a/meta-oe/recipes-dbs/postgresql/files/CVE-2021-23214.patch b/meta-oe/recipes-dbs/postgresql/files/CVE-2021-23214.patch
new file mode 100644
index 000000000..58bf81062
--- /dev/null
+++ b/meta-oe/recipes-dbs/postgresql/files/CVE-2021-23214.patch
@@ -0,0 +1,116 @@
+From 24c2b9e42edb6d2f4ef2cead3b0aa1d6196adfce Mon Sep 17 00:00:00 2001
+From: Tom Lane <tgl@sss.pgh.pa.us>
+Date: Mon, 8 Nov 2021 11:01:43 -0500
+Subject: [PATCH 2/2] Reject extraneous data after SSL or GSS encryption
+ handshake.
+
+The server collects up to a bufferload of data whenever it reads data
+from the client socket.  When SSL or GSS encryption is requested
+during startup, any additional data received with the initial
+request message remained in the buffer, and would be treated as
+already-decrypted data once the encryption handshake completed.
+Thus, a man-in-the-middle with the ability to inject data into the 
+TCP connection could stuff some cleartext data into the start of
+a supposedly encryption-protected database session.
+
+This could be abused to send faked SQL commands to the server,
+although that would only work if the server did not demand any 
+authentication data.  (However, a server relying on SSL certificate
+authentication might well not do so.)
+
+To fix, throw a protocol-violation error if the internal buffer
+is not empty after the encryption handshake.
+
+Our thanks to Jacob Champion for reporting this problem.
+
+Security: CVE-2021-23214
+
+Upstream-Status: Backport[https://github.com/postgres/postgres/commit/28e24125541545483093819efae9bca603441951]
+CVE: CVE-2021-23214
+
+Signed-off-by: Changqing Li <changqing.li@windriver.com>
+
+---
+ src/backend/libpq/pqcomm.c          | 11 +++++++++++
+ src/backend/postmaster/postmaster.c | 23 ++++++++++++++++++++++-
+ src/include/libpq/libpq.h           |  1 +
+ 3 files changed, 34 insertions(+), 1 deletion(-)
+
+diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
+index ee2cd86..4dd1c02 100644
+--- a/src/backend/libpq/pqcomm.c
++++ b/src/backend/libpq/pqcomm.c
+@@ -1183,6 +1183,17 @@ pq_getstring(StringInfo s)
+        }
+ }
+ 
++/* -------------------------------
++ *             pq_buffer_has_data              - is any buffered data available to read?
++ *
++ * This will *not* attempt to read more data.
++ * --------------------------------
++ */
++bool
++pq_buffer_has_data(void)
++{
++       return (PqRecvPointer < PqRecvLength);
++}
+ 
+ /* --------------------------------
+  *             pq_startmsgread - begin reading a message from the client.
+diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
+index 5775fc0..1fcc3f8 100644
+--- a/src/backend/postmaster/postmaster.c
++++ b/src/backend/postmaster/postmaster.c
+@@ -2049,6 +2049,17 @@ retry1:
+                        return STATUS_ERROR;
+ #endif
+ 
++               /*
++               * At this point we should have no data already buffered.  If we do,
++               * it was received before we performed the SSL handshake, so it wasn't
++               * encrypted and indeed may have been injected by a man-in-the-middle.
++               * We report this case to the client.
++               */
++               if (pq_buffer_has_data())
++                       ereport(FATAL,
++                               (errcode(ERRCODE_PROTOCOL_VIOLATION),
++                               errmsg("received unencrypted data after SSL request"),
++                               errdetail("This could be either a client-software bug or evidence of an attempted man-in-the-middle attack.")));
+                /*
+                 * regular startup packet, cancel, etc packet should follow, but not
+                 * another SSL negotiation request, and a GSS request should only
+@@ -2080,7 +2091,17 @@ retry1:
+                if (GSSok == 'G' && secure_open_gssapi(port) == -1)
+                        return STATUS_ERROR;
+ #endif
+-
++               /*
++               * At this point we should have no data already buffered.  If we do,
++               * it was received before we performed the GSS handshake, so it wasn't
++               * encrypted and indeed may have been injected by a man-in-the-middle.
++               * We report this case to the client.
++               */
++               if (pq_buffer_has_data())
++                       ereport(FATAL,
++                               (errcode(ERRCODE_PROTOCOL_VIOLATION),
++                               errmsg("received unencrypted data after GSSAPI encryption request"),
++                               errdetail("This could be either a client-software bug or evidence of an attempted man-in-the-middle attack.")));
+                /*
+                 * regular startup packet, cancel, etc packet should follow, but not
+                 * another GSS negotiation request, and an SSL request should only
+diff --git a/src/include/libpq/libpq.h b/src/include/libpq/libpq.h
+index b115247..9969692 100644
+--- a/src/include/libpq/libpq.h
++++ b/src/include/libpq/libpq.h
+@@ -73,6 +73,7 @@ extern int    pq_getbyte(void);
+ extern int     pq_peekbyte(void);
+ extern int     pq_getbyte_if_available(unsigned char *c);
+ extern int     pq_putbytes(const char *s, size_t len);
++extern bool pq_buffer_has_data(void);
+ 
+ /*
+  * prototypes for functions in be-secure.c
+-- 
+2.17.1
+
diff --git a/meta-oe/recipes-dbs/postgresql/files/CVE-2021-23222.patch b/meta-oe/recipes-dbs/postgresql/files/CVE-2021-23222.patch
new file mode 100644
index 000000000..42b78539b
--- /dev/null
+++ b/meta-oe/recipes-dbs/postgresql/files/CVE-2021-23222.patch
@@ -0,0 +1,131 @@
+From 79125ead2a6a234086844bb42f06d49603fe6ca0 Mon Sep 17 00:00:00 2001
+From: Tom Lane <tgl@sss.pgh.pa.us>
+Date: Mon, 8 Nov 2021 11:14:56 -0500
+Subject: [PATCH 1/2] libpq: reject extraneous data after SSL or GSS encryption
+ handshake.
+
+libpq collects up to a bufferload of data whenever it reads data from
+the socket.  When SSL or GSS encryption is requested during startup,
+any additional data received with the server's yes-or-no reply
+remained in the buffer, and would be treated as already-decrypted data
+once the encryption handshake completed.  Thus, a man-in-the-middle
+with the ability to inject data into the TCP connection could stuff
+some cleartext data into the start of a supposedly encryption-protected
+database session.
+
+This could probably be abused to inject faked responses to the
+client's first few queries, although other details of libpq's behavior
+make that harder than it sounds.  A different line of attack is to
+exfiltrate the client's password, or other sensitive data that might
+be sent early in the session.  That has been shown to be possible with
+a server vulnerable to CVE-2021-23214.
+
+To fix, throw a protocol-violation error if the internal buffer
+is not empty after the encryption handshake.
+
+Our thanks to Jacob Champion for reporting this problem.
+
+Security: CVE-2021-23222
+
+Upstream-Status: Backport[https://github.com/postgres/postgres/commit/160c0258802d10b0600d7671b1bbea55d8e17d45]
+CVE: CVE-2021-23222
+
+Signed-off-by: Changqing Li <changqing.li@windriver.com>
+---
+ doc/src/sgml/protocol.sgml        | 28 ++++++++++++++++++++++++++++
+ src/interfaces/libpq/fe-connect.c | 26 ++++++++++++++++++++++++++
+ 2 files changed, 54 insertions(+)
+
+diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
+index e26619e1b5..b692648fca 100644
+--- a/doc/src/sgml/protocol.sgml
++++ b/doc/src/sgml/protocol.sgml
+@@ -1471,6 +1471,20 @@ SELCT 1/0;<!-- this typo is intentional -->
+     and proceed without requesting <acronym>SSL</acronym>.
+    </para>
+ 
++   <para>
++    When <acronym>SSL</acronym> encryption can be performed, the server
++    is expected to send only the single <literal>S</literal> byte and then
++    wait for the frontend to initiate an <acronym>SSL</acronym> handshake.
++    If additional bytes are available to read at this point, it likely
++    means that a man-in-the-middle is attempting to perform a
++    buffer-stuffing attack
++    (<ulink url="https://www.postgresql.org/support/security/CVE-2021-23222/">CVE-2021-23222</ulink>).
++    Frontends should be coded either to read exactly one byte from the
++    socket before turning the socket over to their SSL library, or to
++    treat it as a protocol violation if they find they have read additional
++    bytes.
++   </para>
++
+    <para>
+     An initial SSLRequest can also be used in a connection that is being
+     opened to send a CancelRequest message.
+@@ -1532,6 +1546,20 @@ SELCT 1/0;<!-- this typo is intentional -->
+     encryption.
+    </para>
+ 
++   <para>
++    When <acronym>GSSAPI</acronym> encryption can be performed, the server
++    is expected to send only the single <literal>G</literal> byte and then
++    wait for the frontend to initiate a <acronym>GSSAPI</acronym> handshake.
++    If additional bytes are available to read at this point, it likely
++    means that a man-in-the-middle is attempting to perform a
++    buffer-stuffing attack
++    (<ulink url="https://www.postgresql.org/support/security/CVE-2021-23222/">CVE-2021-23222</ulink>).
++    Frontends should be coded either to read exactly one byte from the
++    socket before turning the socket over to their GSSAPI library, or to
++    treat it as a protocol violation if they find they have read additional
++    bytes.
++   </para>
++
+    <para>
+     An initial GSSENCRequest can also be used in a connection that is being
+     opened to send a CancelRequest message.
+diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
+index f80f4e98d8..57aee95183 100644
+--- a/src/interfaces/libpq/fe-connect.c
++++ b/src/interfaces/libpq/fe-connect.c
+@@ -3076,6 +3076,19 @@ keep_going:                                              /* We will come back to here until there is
+                                pollres = pqsecure_open_client(conn);
+                                if (pollres == PGRES_POLLING_OK)
+                                {
++                                       /*
++                                        * At this point we should have no data already buffered.
++                                        * If we do, it was received before we performed the SSL
++                                        * handshake, so it wasn't encrypted and indeed may have
++                                        * been injected by a man-in-the-middle.
++                                        */
++                                       if (conn->inCursor != conn->inEnd)
++                                       {
++                                               appendPQExpBufferStr(&conn->errorMessage,
++                                                                                        libpq_gettext("received unencrypted data after SSL response\n"));
++                                               goto error_return;
++                                       }
++
+                                        /* SSL handshake done, ready to send startup packet */
+                                        conn->status = CONNECTION_MADE;
+                                        return PGRES_POLLING_WRITING;
+@@ -3175,6 +3188,19 @@ keep_going:                                              /* We will come back to here until there is
+                                pollres = pqsecure_open_gss(conn);
+                                if (pollres == PGRES_POLLING_OK)
+                                {
++                                       /*
++                                        * At this point we should have no data already buffered.
++                                        * If we do, it was received before we performed the GSS
++                                        * handshake, so it wasn't encrypted and indeed may have
++                                        * been injected by a man-in-the-middle.
++                                        */
++                                       if (conn->inCursor != conn->inEnd)
++                                       {
++                                               appendPQExpBufferStr(&conn->errorMessage,
++                                                                                        libpq_gettext("received unencrypted data after GSSAPI encryption response\n"));
++                                               goto error_return;
++                                       }
++
+                                        /* All set for startup packet */
+                                        conn->status = CONNECTION_MADE;
+                                        return PGRES_POLLING_WRITING;
+-- 
+2.17.1
+
diff --git a/meta-oe/recipes-dbs/postgresql/postgresql_13.4.bb b/meta-oe/recipes-dbs/postgresql/postgresql_13.4.bb
index f63d23dbe..2ed0fa49b 100644
--- a/meta-oe/recipes-dbs/postgresql/postgresql_13.4.bb
+++ b/meta-oe/recipes-dbs/postgresql/postgresql_13.4.bb
@@ -7,6 +7,8 @@ SRC_URI += "\
    file://0001-Add-support-for-RISC-V.patch \
    file://0001-Improve-reproducibility.patch \
    file://0001-configure.in-bypass-autoconf-2.69-version-check.patch \
+   file://CVE-2021-23214.patch \
+   file://CVE-2021-23222.patch \
 "
 
 SRC_URI[sha256sum] = "ea93e10390245f1ce461a54eb5f99a48d8cabd3a08ce4d652ec2169a357bc0cd"