6.6-stable review patch. If anyone has any objections, please let me know.
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From: Michael Kelley mhklinux@outlook.com
[ Upstream commit 7241c886a71797cc51efc6fadec7076fcf6435c2 ]
When a Hyper-V framebuffer device is removed, or the driver is unbound from a device, any allocated and/or mapped memory must be released. In particular, MMIO address space that was mapped to the framebuffer must be unmapped. Current code unmaps the wrong address, resulting in an error like:
[ 4093.980597] iounmap: bad address 00000000c936c05c
followed by a stack dump.
Commit d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver") changed the kind of address stored in info->screen_base, and the iounmap() call in hvfb_putmem() was not updated accordingly.
Fix this by updating hvfb_putmem() to unmap the correct address.
Fixes: d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver") Signed-off-by: Michael Kelley mhklinux@outlook.com Reviewed-by: Saurabh Sengar ssengar@linux.microsoft.com Link: https://lore.kernel.org/r/20250209235252.2987-1-mhklinux@outlook.com Signed-off-by: Wei Liu wei.liu@kernel.org Message-ID: 20250209235252.2987-1-mhklinux@outlook.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/video/fbdev/hyperv_fb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c index b9965cbdd7642..80e8ec36b7db2 100644 --- a/drivers/video/fbdev/hyperv_fb.c +++ b/drivers/video/fbdev/hyperv_fb.c @@ -1106,7 +1106,7 @@ static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
if (par->need_docopy) { vfree(par->dio_vp); - iounmap(info->screen_base); + iounmap(par->mmio_vp); vmbus_free_mmio(par->mem->start, screen_fb_size); } else { hvfb_release_phymem(hdev, info->fix.smem_start,