[097/190] Revert "video: imsttfb: fix potential NULL pointer dereferences"
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Message ID 20210421130105.1226686-98-gregkh@linuxfoundation.org
State New, archived
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Series
  • Revertion of all of the umn.edu commits
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Commit Message

Greg KH April 21, 2021, 12:59 p.m. UTC
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>
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(-)

Comments

Rob Herring April 22, 2021, 2:13 a.m. UTC | #1
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.

Rob
Greg KH April 27, 2021, 3 p.m. UTC | #2
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

Patch
diff mbox series

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;
-	}
 	info->fix.mmio_start = addr + 0x800000;
 	par->dc_regs = ioremap(addr + 0x800000, 0x1000);
 	par->cmap_regs_phys = addr + 0x840000;