Thanks for your patch.
I would like to change the prefix to "video: hyperv_fb:" to be more
specific.
On Tue, Mar 23, 2021 at 12:33:50AM -0700, Lv Yunlong wrote:
In function hvfb_probe in hyperv_fb.c, it calls hvfb_getmem(hdev, info)
and return err when info->apertures is freed.
In the error1 label of hvfb_probe, info->apertures will be freed twice
by framebuffer_release(info).
I would say "freed for the second time" here. What you wrote reads to me
fraembuffer_release frees the buffer twice all by itself.
My patch sets info->apertures to NULL after it was freed to avoid
double free.
I think this approach works. I would like to give other people a chance
to comment though.
Fixes: 3a6fb6c4255c ("video: hyperv: hyperv_fb: Use physical memory for fb on HyperV Gen 1 VMs.")
quoted hunk ↗ jump to hunk
Signed-off-by: Lv Yunlong <redacted>
---
drivers/video/fbdev/hyperv_fb.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index c8b0ae676809..2fc9b507e73a 100644
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -1032,6 +1032,7 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
if (!pdev) {
pr_err("Unable to find PCI Hyper-V video\n");
kfree(info->apertures);
+ info->apertures = NULL;
return -ENODEV;
}
@@ -1130,6 +1131,7 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
pci_dev_put(pdev);
}
kfree(info->apertures);
+ info->apertures = NULL;
return 0;
@@ -1142,6 +1144,7 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
if (!gen2vm)
pci_dev_put(pdev);
kfree(info->apertures);
+ info->apertures = NULL;
return -ENOMEM;
}
--
2.25.1