From 4b5b4721464495fe76fe6e2e033cbb61dce78eef Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Thu, 22 Aug 2013 11:43:58 +0200 Subject: [PATCH] chardev: fix pty_chr_timer 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 Cc: qemu-stable@nongnu.org Signed-off-by: Gerd Hoffmann (cherry picked from commit b0d768c35e08d2057b63e8e77e7a513c447199fa) Signed-off-by: Michael Roth --- 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; }