1 files changed, 52 insertions, 0 deletions

diff --git a/meta/recipes-multimedia/pulseaudio/pulseaudio/CVE-2014-3970.patch b/meta/recipes-multimedia/pulseaudio/pulseaudio/CVE-2014-3970.patch
new file mode 100644
index 0000000000..d5f33dc42e
--- /dev/null
+++ b/meta/recipes-multimedia/pulseaudio/pulseaudio/CVE-2014-3970.patch
@@ -0,0 +1,52 @@
+Upstream-Status: Backport
+
+commit 26b9d22dd24c17eb118d0205bf7b02b75d435e3c upstream
+
+rtp-recv: fix crash on empty UDP packets (CVE-2014-3970)
+
+On FIONREAD returning 0 bytes, we cannot return success, as the caller
+(rtpoll_work_cb in module-rtp-recv.c) would then try to
+pa_memblock_unref(chunk.memblock) and, because memblock is NULL, trigger
+an assertion.
+
+Also we have to read out the possible empty packet from the socket, so
+that the kernel doesn't tell us again and again about it.
+
+Signed-off-by: Alexander E. Patrakov <patrakov@gmail.com>
+
+diff --git a/src/modules/rtp/rtp.c b/src/modules/rtp/rtp.c
+index 9195493..c45981e 100644
+--- a/src/modules/rtp/rtp.c
++++ b/src/modules/rtp/rtp.c
+@@ -182,8 +182,29 @@ int pa_rtp_recv(pa_rtp_context *c, pa_memchunk *chunk, pa_mempool *pool, struct
+         goto fail;
+     }
+ 
+-    if (size <= 0)
+-        return 0;
++    if (size <= 0) {
++        /* size can be 0 due to any of the following reasons:
++         *
++         * 1. Somebody sent us a perfectly valid zero-length UDP packet.
++         * 2. Somebody sent us a UDP packet with a bad CRC.
++         *
++         * It is unknown whether size can actually be less than zero.
++         *
++         * In the first case, the packet has to be read out, otherwise the
++         * kernel will tell us again and again about it, thus preventing
++         * reception of any further packets. So let's just read it out
++         * now and discard it later, when comparing the number of bytes
++         * received (0) with the number of bytes wanted (1, see below).
++         *
++         * In the second case, recvmsg() will fail, thus allowing us to
++         * return the error.
++         *
++         * Just to avoid passing zero-sized memchunks and NULL pointers to
++         * recvmsg(), let's force allocation of at least one byte by setting
++         * size to 1.
++         */
++        size = 1;
++    }
+ 
+     if (c->memchunk.length < (unsigned) size) {
+         size_t l;