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authorChristophe JAILLET <christophe.jaillet@wanadoo.fr>2020-05-06 20:19:02 +0200
committerSam Ravnborg <sam@ravnborg.org>2020-05-06 20:22:25 +0200
commit18722d48a6bb9c2e8d046214c0a5fd19d0a7c9f6 (patch)
tree647206bfdb3215f21be71722a7c4dfbcf6dc45c8
parentd163a95cf00130d8d980cbf16675337caeb9cdad (diff)
downloadlinux-18722d48a6bb9c2e8d046214c0a5fd19d0a7c9f6.tar.gz
video: fbdev: w100fb: Fix a potential double free.
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
-rw-r--r--drivers/video/fbdev/w100fb.c2
1 files changed, 2 insertions, 0 deletions
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;
 	}
 }