lkml.org 
[lkml]   [2020]   [May]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V2] video: fbdev: w100fb: Fix a potential double free.
Hi Christophe
On Wed, May 06, 2020 at 08:19:02PM +0200, Christophe JAILLET wrote:
> Some memory is vmalloc'ed in the 'w100fb_save_vidmem' function and freed in
> the 'w100fb_restore_vidmem' function. (these functions are called
> respectively from the 'suspend' and the 'resume' functions)
>
> However, it is also freed in the 'remove' function.
>
> In order to avoid a potential double free, set the corresponding pointer
> to NULL once freed in the 'w100fb_restore_vidmem' function.
>
> Fixes: aac51f09d96a ("[PATCH] w100fb: Rewrite for platform independence")
> Cc: Richard Purdie <rpurdie@rpsys.net>
> Cc: Antonino Daplas <adaplas@pol.net>
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> Cc: <stable@vger.kernel.org> # v2.6.14+
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

Thanks for the quick v2.
Applied to drm-misc-next.

Sam

> ---
> v2: - Add Cc: tags
> - Reword the commit message to give the names of the functions that
> allocate and free the memory. These functions are called from the
> suspend and resume function.
> ---
> drivers/video/fbdev/w100fb.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/video/fbdev/w100fb.c b/drivers/video/fbdev/w100fb.c
> index 2d6e2738b792..d96ab28f8ce4 100644
> --- a/drivers/video/fbdev/w100fb.c
> +++ b/drivers/video/fbdev/w100fb.c
> @@ -588,6 +588,7 @@ static void w100fb_restore_vidmem(struct w100fb_par *par)
> memsize=par->mach->mem->size;
> memcpy_toio(remapped_fbuf + (W100_FB_BASE-MEM_WINDOW_BASE), par->saved_extmem, memsize);
> vfree(par->saved_extmem);
> + par->saved_extmem = NULL;
> }
> if (par->saved_intmem) {
> memsize=MEM_INT_SIZE;
> @@ -596,6 +597,7 @@ static void w100fb_restore_vidmem(struct w100fb_par *par)
> else
> memcpy_toio(remapped_fbuf + (W100_FB_BASE-MEM_WINDOW_BASE), par->saved_intmem, memsize);
> vfree(par->saved_intmem);
> + par->saved_intmem = NULL;
> }
> }
>
> --
> 2.25.1

\
 
 \ /
  Last update: 2020-05-06 20:23    [W:0.046 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site