From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34631) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VCRdz-000242-03 for qemu-devel@nongnu.org; Thu, 22 Aug 2013 05:57:37 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VCRdt-0001Us-0m for qemu-devel@nongnu.org; Thu, 22 Aug 2013 05:57:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45023) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VCRds-0001Uj-P4 for qemu-devel@nongnu.org; Thu, 22 Aug 2013 05:57:24 -0400 From: Gerd Hoffmann Date: Thu, 22 Aug 2013 11:57:21 +0200 Message-Id: <1377165441-28827-1-git-send-email-kraxel@redhat.com> Subject: [Qemu-devel] [PATCH] chardev: fix pty_chr_timer List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Gerd Hoffmann , Anthony Liguori pty_chr_timer first calls pty_chr_update_read_handler(), then clears timer_tag (because it is a one-shot timer). This is the wrong order though. pty_chr_update_read_handler might re-arm time timer, and the new timer_tag gets overwitten in that case. This leads to crashes when unplugging a pty chardev: pty_chr_close thinks no timer is running -> timer isn't canceled -> pty_chr_timer gets called with stale CharDevState -> BOOM. This patch fixes the ordering. Kill the pointless goto while being at it. https://bugzilla.redhat.com/show_bug.cgi?id=994414 Signed-off-by: Gerd Hoffmann --- qemu-char.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/qemu-char.c b/qemu-char.c index 1be1cf6..1621fbd 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -1026,15 +1026,11 @@ static gboolean pty_chr_timer(gpointer opaque) struct CharDriverState *chr = opaque; PtyCharDriver *s = chr->opaque; - if (s->connected) { - goto out; - } - - /* Next poll ... */ - pty_chr_update_read_handler(chr); - -out: s->timer_tag = 0; + if (!s->connected) { + /* Next poll ... */ + pty_chr_update_read_handler(chr); + } return FALSE; } -- 1.8.3.1