From 0d3d5099a50badadad6837edda00e42149b2f657 Mon Sep 17 00:00:00 2001
From: Zheng Wang <zyytlz.wz@163.com>
Date: Fri, 30 Dec 2022 00:56:41 +0800
Subject: [PATCH] drm/i915/gvt: fix double free bug in split_2MB_gtt_entry
commit 4a61648af68f5ba4884f0e3b494ee1cabc4b6620 upstream.
If intel_gvt_dma_map_guest_page failed, it will call
ppgtt_invalidate_spt, which will finally free the spt.
But the caller function ppgtt_populate_spt_by_guest_entry
does not notice that, it will free spt again in its error
path.
Fix this by canceling the mapping of DMA address and freeing sub_spt.
Besides, leave the handle of spt destroy to caller function instead
of callee function when error occurs.
Fixes: b901b252b6cf ("drm/i915/gvt: Add 2M huge gtt support")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20221229165641.1192455-1-zyytlz.wz@163.com
Signed-off-by: Ovidiu Panait <ovidiu.panait@eng.windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/gvt/gtt.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/gvt/gtt.c b/drivers/gpu/drm/i915/gvt/gtt.c
index e5c2fdfc20e33..7ea7abef6143f 100644
--- a/drivers/gpu/drm/i915/gvt/gtt.c
+++ b/drivers/gpu/drm/i915/gvt/gtt.c
@@ -1195,10 +1195,8 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu,
for_each_shadow_entry(sub_spt, &sub_se, sub_index) {
ret = intel_gvt_hypervisor_dma_map_guest_page(vgpu,
start_gfn + sub_index, PAGE_SIZE, &dma_addr);
- if (ret) {
- ppgtt_invalidate_spt(spt);
- return ret;
- }
+ if (ret)
+ goto err;
sub_se.val64 = se->val64;
/* Copy the PAT field from PDE. */
@@ -1217,6 +1215,17 @@ static int split_2MB_gtt_entry(struct intel_vgpu *vgpu,
ops->set_pfn(se, sub_spt->shadow_page.mfn);
ppgtt_set_shadow_entry(spt, se, index);
return 0;
+err:
+ /* Cancel the existing addess mappings of DMA addr. */
+ for_each_present_shadow_entry(sub_spt, &sub_se, sub_index) {
+ gvt_vdbg_mm("invalidate 4K entry\n");
+ ppgtt_invalidate_pte(sub_spt, &sub_se);
+ }
+ /* Release the new allocated spt. */
+ trace_spt_change(sub_spt->vgpu->id, "release", sub_spt,
+ sub_spt->guest_page.gfn, sub_spt->shadow_page.type);
+ ppgtt_free_spt(sub_spt);
+ return ret;
}
static int split_64KB_gtt_entry(struct intel_vgpu *vgpu,
--
2.30.2