|
@@ -0,0 +1,57 @@
|
|
1
|
+From 26b9d22dd24c17eb118d0205bf7b02b75d435e3c Mon Sep 17 00:00:00 2001
|
|
2
|
+From: "Alexander E. Patrakov" <patrakov@gmail.com>
|
|
3
|
+Date: Thu, 5 Jun 2014 22:29:25 +0600
|
|
4
|
+Subject: [PATCH] rtp-recv: fix crash on empty UDP packets (CVE-2014-3970)
|
|
5
|
+
|
|
6
|
+On FIONREAD returning 0 bytes, we cannot return success, as the caller
|
|
7
|
+(rtpoll_work_cb in module-rtp-recv.c) would then try to
|
|
8
|
+pa_memblock_unref(chunk.memblock) and, because memblock is NULL, trigger
|
|
9
|
+an assertion.
|
|
10
|
+
|
|
11
|
+Also we have to read out the possible empty packet from the socket, so
|
|
12
|
+that the kernel doesn't tell us again and again about it.
|
|
13
|
+
|
|
14
|
+Signed-off-by: Alexander E. Patrakov <patrakov@gmail.com>
|
|
15
|
+---
|
|
16
|
+ src/modules/rtp/rtp.c | 25 +++++++++++++++++++++++--
|
|
17
|
+ 1 file changed, 23 insertions(+), 2 deletions(-)
|
|
18
|
+
|
|
19
|
+diff --git a/src/modules/rtp/rtp.c b/src/modules/rtp/rtp.c
|
|
20
|
+index 570737e..7b75e0e 100644
|
|
21
|
+--- a/src/modules/rtp/rtp.c
|
|
22
|
++++ b/src/modules/rtp/rtp.c
|
|
23
|
+@@ -182,8 +182,29 @@ int pa_rtp_recv(pa_rtp_context *c, pa_memchunk *chunk, pa_mempool *pool, struct
|
|
24
|
+ goto fail;
|
|
25
|
+ }
|
|
26
|
+
|
|
27
|
+- if (size <= 0)
|
|
28
|
+- return 0;
|
|
29
|
++ if (size <= 0) {
|
|
30
|
++ /* size can be 0 due to any of the following reasons:
|
|
31
|
++ *
|
|
32
|
++ * 1. Somebody sent us a perfectly valid zero-length UDP packet.
|
|
33
|
++ * 2. Somebody sent us a UDP packet with a bad CRC.
|
|
34
|
++ *
|
|
35
|
++ * It is unknown whether size can actually be less than zero.
|
|
36
|
++ *
|
|
37
|
++ * In the first case, the packet has to be read out, otherwise the
|
|
38
|
++ * kernel will tell us again and again about it, thus preventing
|
|
39
|
++ * reception of any further packets. So let's just read it out
|
|
40
|
++ * now and discard it later, when comparing the number of bytes
|
|
41
|
++ * received (0) with the number of bytes wanted (1, see below).
|
|
42
|
++ *
|
|
43
|
++ * In the second case, recvmsg() will fail, thus allowing us to
|
|
44
|
++ * return the error.
|
|
45
|
++ *
|
|
46
|
++ * Just to avoid passing zero-sized memchunks and NULL pointers to
|
|
47
|
++ * recvmsg(), let's force allocation of at least one byte by setting
|
|
48
|
++ * size to 1.
|
|
49
|
++ */
|
|
50
|
++ size = 1;
|
|
51
|
++ }
|
|
52
|
+
|
|
53
|
+ if (c->memchunk.length < (unsigned) size) {
|
|
54
|
+ size_t l;
|
|
55
|
+--
|
|
56
|
+2.0.0
|
|
57
|
+
|