From: Helge Deller <deller@gmx.de>
To: Arnd Bergmann <arnd@kernel.org>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Javier Martinez Canillas <javierm@redhat.com>,
Arnd Bergmann <arnd@arndb.de>
Cc: kernel test robot <lkp@intel.com>,
Dan Carpenter <dan.carpenter@linaro.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
Michael Kelley <mikelley@microsoft.com>,
"Guilherme G. Piccoli" <gpiccoli@igalia.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Dawei Li <set_pte_at@outlook.com>,
linux-hyperv@vger.kernel.org, linux-fbdev@vger.kernel.org,
dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fbdev: hyperv_fb: fix uninitialized local variable use
Date: Wed, 8 Nov 2023 16:38:34 +0100 [thread overview]
Message-ID: <a320ae82-24ce-4c0d-bae3-b14e43c1f512@gmx.de> (raw)
In-Reply-To: <20231108145822.3955219-1-arnd@kernel.org>
On 11/8/23 15:58, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
>
> When CONFIG_SYSFB is disabled, the hyperv_fb driver can now run into
> undefined behavior on a gen2 VM, as indicated by this smatch warning:
>
> drivers/video/fbdev/hyperv_fb.c:1077 hvfb_getmem() error: uninitialized symbol 'base'.
> drivers/video/fbdev/hyperv_fb.c:1077 hvfb_getmem() error: uninitialized symbol 'size'.
>
> Since there is no way to know the actual framebuffer in this configuration,
> just return an allocation failure here, which should avoid the build
> warning and the undefined behavior.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
> Closes: https://lore.kernel.org/r/202311070802.YCpvehaz-lkp@intel.com/
> Fixes: a07b50d80ab6 ("hyperv: avoid dependency on screen_info")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
applied.
Thanks!
Helge
> ---
> drivers/video/fbdev/hyperv_fb.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
> index bf59daf862fc..a80939fe2ee6 100644
> --- a/drivers/video/fbdev/hyperv_fb.c
> +++ b/drivers/video/fbdev/hyperv_fb.c
> @@ -1013,6 +1013,8 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
> } else if (IS_ENABLED(CONFIG_SYSFB)) {
> base = screen_info.lfb_base;
> size = screen_info.lfb_size;
> + } else {
> + goto err1;
> }
>
> /*
prev parent reply other threads:[~2023-11-08 15:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-08 14:58 [PATCH] fbdev: hyperv_fb: fix uninitialized local variable use Arnd Bergmann
2023-11-08 15:38 ` Helge Deller [this message]
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