| From 8fb3ac70845fbe261407e7782d3e6233e368da8f Mon Sep 17 00:00:00 2001 |
| From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com> |
| Date: Wed, 13 Dec 2017 13:38:37 +0100 |
| Subject: [PATCH 06/41] fw_cfg: avoid calculating invalid current entry pointer |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| RH-Author: Marc-André Lureau <marcandre.lureau@redhat.com> |
| Message-id: <20171213133912.26176-7-marcandre.lureau@redhat.com> |
| Patchwork-id: 78355 |
| O-Subject: [RHEL-7.5 qemu-kvm PATCH v3 06/41] fw_cfg: avoid calculating invalid current entry pointer |
| Bugzilla: 1411490 |
| RH-Acked-by: Laszlo Ersek <lersek@redhat.com> |
| RH-Acked-by: Michael S. Tsirkin <mst@redhat.com> |
| RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com> |
| |
| From: "Gabriel L. Somlo" <somlo@cmu.edu> |
| |
| When calculating a pointer to the currently selected fw_cfg item, the |
| following is used: |
| |
| FWCfgEntry *e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK]; |
| |
| When s->cur_entry is FW_CFG_INVALID, we are calculating the address of |
| a non-existent element in s->entries[arch][...], which is undefined. |
| |
| This patch ensures the resulting entry pointer is set to NULL whenever |
| s->cur_entry is FW_CFG_INVALID. |
| |
| Reported-by: Laszlo Ersek <lersek@redhat.com> |
| Reviewed-by: Laszlo Ersek <lersek@redhat.com> |
| Signed-off-by: Gabriel Somlo <somlo@cmu.edu> |
| Message-id: 1446733972-1602-5-git-send-email-somlo@cmu.edu |
| Cc: Marc Marí <markmb@redhat.com> |
| Signed-off-by: Gabriel Somlo <somlo@cmu.edu> |
| Reviewed-by: Laszlo Ersek <lersek@redhat.com> |
| Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> |
| |
| (cherry picked from commit 66f8fd9dda312191b78d2a2ba2848bcee76127a2) |
| |
| RHEL: fix minor conflicts due to previous partial backport in commit |
| ba24567fd90702ea40ff320a79bc921b38510f22. |
| |
| Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> |
| Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> |
| |
| hw/nvram/fw_cfg.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c |
| index 85e950c..1317df7 100644 |
| |
| |
| @@ -301,7 +301,8 @@ static void fw_cfg_dma_transfer(FWCfgState *s) |
| } |
| |
| arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL); |
| - e = &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK]; |
| + e = (s->cur_entry == FW_CFG_INVALID) ? NULL : |
| + &s->entries[arch][s->cur_entry & FW_CFG_ENTRY_MASK]; |
| |
| if (dma.control & FW_CFG_DMA_CTL_READ) { |
| read = 1; |
| -- |
| 1.8.3.1 |
| |