video: fbdev: w100fb: Fix a potential double free.

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 <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>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200506181902.193290-1-christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Christophe JAILLET 2020-05-06 20:19:02 +02:00 committed by Greg Kroah-Hartman
parent 0926f136f3
commit a624cf5d87

View File

@ -583,6 +583,7 @@ 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;
@ -591,6 +592,7 @@ 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;
}
}