File 0242-qemu-nbd-Ignore-SIGPIPE.patch of Package qemu-linux-user.15026

From c17cc3f02ff5d18036def09e58e36b41acc64bd9 Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Sun, 11 Jun 2017 14:37:14 +0200
Subject: [PATCH] qemu-nbd: Ignore SIGPIPE

qemu proper has done so for 13 years
(8a7ddc38a60648257dc0645ab4a05b33d6040063), qemu-img and qemu-io have
done so for four years (526eda14a68d5b3596be715505289b541288ef2a).
Ignoring this signal is especially important in qemu-nbd because
otherwise a client can easily take down the qemu-nbd server by dropping
the connection when the server wants to send something, for example:

$ qemu-nbd -x foo -f raw -t null-co:// &
[1] 12726
$ qemu-io -c quit nbd://localhost/bar
can't open device nbd://localhost/bar: No export with name 'bar' available
[1]  + 12726 broken pipe  qemu-nbd -x foo -f raw -t null-co://

In this case, the client sends an NBD_OPT_ABORT and closes the
connection (because it is not required to wait for a reply), but the
server replies with an NBD_REP_ACK (because it is required to reply).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20170611123714.31292-1-mreitz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 041e32b8d9d076980b4e35317c0339e57ab888f1)
[FL: BSC#1046636 CVE-2017-10664]
Signed-off-by: Fei Li <fli@suse.com>
---
 qemu-nbd.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/qemu-nbd.c b/qemu-nbd.c
index 0b5e8e5a26..7293e95781 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -521,6 +521,10 @@ int main(int argc, char **argv)
     sa_sigterm.sa_handler = termsig_handler;
     sigaction(SIGTERM, &sa_sigterm, NULL);
 
+#ifdef CONFIG_POSIX
+    signal(SIGPIPE, SIG_IGN);
+#endif
+
     if (qcrypto_init(&local_err) < 0) {
         error_reportf_err(local_err, "cannot initialize crypto: ");
         exit(1);