Messages in this thread Patch in this message |  | | | Date | Sun, 27 Apr 2008 12:46:22 +0200 (CEST) | | From | Julia Lawall <> | | Subject | [PATCH] drivers/video/pnx4008: eliminate double free |
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From: Julia Lawall <julia@diku.dk>
The function framebuffer_release just calls kfree, so calling kfree subsequently on the same argument represents a double free. The comments with the definition of framebuffer_release in drivers/video/fbsysfs.c suggest that a more elaborate definition of this function is planned, such that the splitting up of framebuffer_release and kfree as done in the second instance might someday make sense, but it does not make sense now.
This was found using the following semantic match. (http://www.emn.fr/x-info/coccinelle/)
// <smpl> @@ expression E; @@
* kfree(E); ... * framebuffer_release(E);
@@ expression E; @@
* framebuffer_release(E); ... * kfree(E); // </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk> --- diff -u -p a/drivers/video/pnx4008/pnxrgbfb.c b/drivers/video/pnx4008/pnxrgbfb.c --- a/drivers/video/pnx4008/pnxrgbfb.c 2008-04-07 13:50:27.000000000 +0200 +++ b/drivers/video/pnx4008/pnxrgbfb.c 2008-04-27 12:25:52.000000000 +0200 @@ -100,7 +100,6 @@ static int rgbfb_remove(struct platform_ fb_dealloc_cmap(&info->cmap); framebuffer_release(info); platform_set_drvdata(pdev, NULL); - kfree(info); } pnx4008_free_dum_channel(channel_owned, pdev->id); @@ -168,23 +167,21 @@ static int __devinit rgbfb_probe(struct ret = fb_alloc_cmap(&info->cmap, 256, 0); if (ret < 0) - goto err2; + goto err1; ret = register_framebuffer(info); if (ret < 0) - goto err3; + goto err2; platform_set_drvdata(pdev, info); return 0; -err3: - fb_dealloc_cmap(&info->cmap); err2: - framebuffer_release(info); + fb_dealloc_cmap(&info->cmap); err1: pnx4008_free_dum_channel(channel_owned, pdev->id); err0: - kfree(info); + framebuffer_release(info); err: return ret; }
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