* [PATCH V2] video: fbdev: w100fb: Fix a potential double free.
@ 2020-05-06 18:19 Christophe JAILLET
2020-05-06 18:23 ` Sam Ravnborg
0 siblings, 1 reply; 2+ messages in thread
From: Christophe JAILLET @ 2020-05-06 18:19 UTC (permalink / raw)
To: rpurdie, adaplas, b.zolnierkie, sam
Cc: linux-fbdev, kernel-janitors, linux-kernel, stable,
Christophe JAILLET, dri-devel
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>
---
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
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V2] video: fbdev: w100fb: Fix a potential double free.
2020-05-06 18:19 [PATCH V2] video: fbdev: w100fb: Fix a potential double free Christophe JAILLET
@ 2020-05-06 18:23 ` Sam Ravnborg
0 siblings, 0 replies; 2+ messages in thread
From: Sam Ravnborg @ 2020-05-06 18:23 UTC (permalink / raw)
To: Christophe JAILLET
Cc: linux-fbdev, b.zolnierkie, kernel-janitors, linux-kernel,
dri-devel, rpurdie, stable, adaplas
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
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2020-05-07 7:06 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-06 18:19 [PATCH V2] video: fbdev: w100fb: Fix a potential double free Christophe JAILLET
2020-05-06 18:23 ` Sam Ravnborg
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).