Re: [PATCH 097/190] Revert "video: imsttfb: fix potential NULL pointer dereferences"

Greg Kroah-Hartman
2021-04-27T15:00:51Z

On Wed, Apr 21, 2021 at 09:13:29PM -0500, Rob Herring wrote:
> On Wed, Apr 21, 2021 at 8:05 AM Greg Kroah-Hartman
> <gregkh@linuxfoundation.org> wrote:
> >
> > This reverts commit 1d84353d205a953e2381044953b7fa31c8c9702d.
> >
> > Commits from @umn.edu addresses have been found to be submitted in "bad
> > faith" to try to test the kernel community's ability to review "known
> > malicious" changes. The result of these submissions can be found in a
> > paper published at the 42nd IEEE Symposium on Security and Privacy
> > entitled, "Open Source Insecurity: Stealthily Introducing
> > Vulnerabilities via Hypocrite Commits" written by Qiushi Wu (University
> > of Minnesota) and Kangjie Lu (University of Minnesota).
> >
> > Because of this, all submissions from this group must be reverted from
> > the kernel tree and will need to be re-reviewed again to determine if
> > they actually are a valid fix. Until that work is complete, remove this
> > change to ensure that no problems are being introduced into the
> > codebase.
> >
> > Cc: Kangjie Lu <kjlu@umn.edu>
> > Cc: Aditya Pakki <pakki001@umn.edu>
> > Cc: Finn Thain <fthain@telegraphics.com.au>
> > Cc: Rob Herring <robh@kernel.org>
>
> Sigh, get_maintainers.pl likes to punish people for treewide clean-ups...
>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > ---
> > drivers/video/fbdev/imsttfb.c | 5 -----
> > 1 file changed, 5 deletions(-)
> >
> > diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
> > index 3ac053b88495..e04411701ec8 100644
> > --- a/drivers/video/fbdev/imsttfb.c
> > +++ b/drivers/video/fbdev/imsttfb.c
> > @@ -1512,11 +1512,6 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
> > info->fix.smem_start = addr;
> > info->screen_base = (__u8 *)ioremap(addr, par->ramdac == IBM ?
> > 0x400000 : 0x800000);
> > - if (!info->screen_base) {
> > - release_mem_region(addr, size);
> > - framebuffer_release(info);
> > - return -ENOMEM;
> > - }
>
> The original change appears to be valid, but incomplete...
>
> > info->fix.mmio_start = addr + 0x800000;
> > par->dc_regs = ioremap(addr + 0x800000, 0x1000);
>
> ...because what about cleanup when this ioremap fails.
>
> > par->cmap_regs_phys = addr + 0x840000;
>
> Then again, if anyone really cared about this driver and h/w (a
> PowerMac era PCI display card), it would not still be using fbdev and
> would use devm_* apis.

Thanks for the review, I've updated the changelog to reflect this mess :)

greg k-h