From: Christophe JAILLET <christophe.jail...@wanadoo.fr>

commit 18722d48a6bb9c2e8d046214c0a5fd19d0a7c9f6 upstream.

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 <rpur...@rpsys.net>
Cc: Antonino Daplas <adap...@pol.net>
Cc: Bartlomiej Zolnierkiewicz <b.zolnier...@samsung.com>
Cc: <sta...@vger.kernel.org> # v2.6.14+
Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
Signed-off-by: Sam Ravnborg <s...@ravnborg.org>
Link: 
https://patchwork.freedesktop.org/patch/msgid/20200506181902.193290-1-christophe.jail...@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/video/fbdev/w100fb.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/video/fbdev/w100fb.c
+++ b/drivers/video/fbdev/w100fb.c
@@ -583,6 +583,7 @@ static void w100fb_restore_vidmem(struct
                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;
@@ -591,6 +592,7 @@ static void w100fb_restore_vidmem(struct
                else
                        memcpy_toio(remapped_fbuf + 
(W100_FB_BASE-MEM_WINDOW_BASE), par->saved_intmem, memsize);
                vfree(par->saved_intmem);
+               par->saved_intmem = NULL;
        }
 }
 


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