57 lines
2.0 KiB
Diff
57 lines
2.0 KiB
Diff
From 04eefabaae59ad624f0baf3b97a1d1d15cf2a23d Mon Sep 17 00:00:00 2001
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From: David Gibson <david@gibson.dropbear.id.au>
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Date: Mon, 10 Sep 2012 12:30:56 +1000
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Subject: [PATCH] qemu-char: BUGFIX, don't call FD_ISSET with negative fd
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tcp_chr_connect(), unlike for example udp_chr_update_read_handler() does
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not check if the fd it is using is valid (>= 0) before passing it to
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qemu_set_fd_handler2(). If using e.g. a TCP serial port, which is not
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initially connected, this can result in -1 being passed to FD_ISSET, which
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has undefined behaviour. On x86 it seems to harmlessly return 0, but on
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PowerPC, it causes a fortify buffer overflow error to be thrown.
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This patch fixes this by putting an extra test in tcp_chr_connect(), and
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also adds an assert qemu_set_fd_handler2() to catch other such errors on
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all platforms, rather than just some.
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Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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(cherry picked from commit bbdd2ad0814ea0911076419ea21b7957505cf1cc)
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Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
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---
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iohandler.c | 2 ++
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qemu-char.c | 6 ++++--
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2 files changed, 6 insertions(+), 2 deletions(-)
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diff --git a/iohandler.c b/iohandler.c
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index dea4355..a2d871b 100644
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--- a/iohandler.c
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+++ b/iohandler.c
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@@ -56,6 +56,8 @@ int qemu_set_fd_handler2(int fd,
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{
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IOHandlerRecord *ioh;
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+ assert(fd >= 0);
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+
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if (!fd_read && !fd_write) {
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QLIST_FOREACH(ioh, &io_handlers, next) {
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if (ioh->fd == fd) {
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diff --git a/qemu-char.c b/qemu-char.c
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index 10d1504..7f0f895 100644
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--- a/qemu-char.c
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+++ b/qemu-char.c
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@@ -2329,8 +2329,10 @@ static void tcp_chr_connect(void *opaque)
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TCPCharDriver *s = chr->opaque;
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s->connected = 1;
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- qemu_set_fd_handler2(s->fd, tcp_chr_read_poll,
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- tcp_chr_read, NULL, chr);
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+ if (s->fd >= 0) {
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+ qemu_set_fd_handler2(s->fd, tcp_chr_read_poll,
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+ tcp_chr_read, NULL, chr);
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+ }
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qemu_chr_generic_open(chr);
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}
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