From 18c4fbe13ce03654f763f6569bb740c57109555c Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 10 Jul 2017 17:52:18 +0200 Subject: [PATCH] qemu-nbd: Ignore SIGPIPE RH-Author: Eric Blake Message-id: <20170710175218.13682-1-eblake@redhat.com> Patchwork-id: 75718 O-Subject: [RHEL-7.4.z qemu-kvm PATCH] qemu-nbd: Ignore SIGPIPE Bugzilla: 1466463 RH-Acked-by: John Snow RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Paolo Bonzini From: Max Reitz 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 Message-Id: <20170611123714.31292-1-mreitz@redhat.com> Signed-off-by: Paolo Bonzini (cherry picked from commit 041e32b8d9d076980b4e35317c0339e57ab888f1) Signed-off-by: Miroslav Rezanina Conflicts: qemu-nbd.c - context Fixes CVE-2017-10664 Signed-off-by: Eric Blake --- qemu-nbd.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/qemu-nbd.c b/qemu-nbd.c index e0f4517..fc768eb 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -363,6 +363,11 @@ int main(int argc, char **argv) memset(&sa_sigterm, 0, sizeof(sa_sigterm)); sa_sigterm.sa_handler = termsig_handler; sigaction(SIGTERM, &sa_sigterm, NULL); + +#ifdef CONFIG_POSIX + signal(SIGPIPE, SIG_IGN); +#endif + qemu_init_exec_dir(argv[0]); while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { -- 1.8.3.1