* [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference
@ 2015-09-04 11:42 Sudip Mukherjee
2015-09-10 18:03 ` David Cohen
0 siblings, 1 reply; 6+ messages in thread
From: Sudip Mukherjee @ 2015-09-04 11:42 UTC (permalink / raw)
To: Thomas Dahlmann, Felipe Balbi, Greg Kroah-Hartman
Cc: linux-kernel, linux-geode, linux-usb, Sudip Mukherjee
We were checking if dev->regs is NULL but it was done after
dereferencing it. Lets reset the controller and iounmap dev->regs only
if it is not NULL.
free_irq() does not need dev->regs, so unmaping it before freeing the
irq should not matter.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
---
drivers/usb/gadget/udc/amd5536udc.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
index fdacddb..26066d3 100644
--- a/drivers/usb/gadget/udc/amd5536udc.c
+++ b/drivers/usb/gadget/udc/amd5536udc.c
@@ -3135,11 +3135,12 @@ static void udc_pci_remove(struct pci_dev *pdev)
}
/* reset controller */
- writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
+ if (dev->regs) {
+ writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
+ iounmap(dev->regs);
+ }
if (dev->irq_registered)
free_irq(pdev->irq, dev);
- if (dev->regs)
- iounmap(dev->regs);
if (dev->mem_region)
release_mem_region(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0));
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference
2015-09-04 11:42 [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference Sudip Mukherjee
@ 2015-09-10 18:03 ` David Cohen
2015-09-11 10:02 ` Sudip Mukherjee
0 siblings, 1 reply; 6+ messages in thread
From: David Cohen @ 2015-09-10 18:03 UTC (permalink / raw)
To: Sudip Mukherjee
Cc: Thomas Dahlmann, Felipe Balbi, Greg Kroah-Hartman, linux-kernel,
linux-geode, linux-usb
Hi Sudip,
On Fri, Sep 04, 2015 at 05:12:23PM +0530, Sudip Mukherjee wrote:
> We were checking if dev->regs is NULL but it was done after
> dereferencing it. Lets reset the controller and iounmap dev->regs only
> if it is not NULL.
> free_irq() does not need dev->regs, so unmaping it before freeing the
> irq should not matter.
>
> Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> ---
> drivers/usb/gadget/udc/amd5536udc.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
> index fdacddb..26066d3 100644
> --- a/drivers/usb/gadget/udc/amd5536udc.c
> +++ b/drivers/usb/gadget/udc/amd5536udc.c
> @@ -3135,11 +3135,12 @@ static void udc_pci_remove(struct pci_dev *pdev)
> }
>
> /* reset controller */
> - writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
> + if (dev->regs) {
> + writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
> + iounmap(dev->regs);
I'm not familiar with the driver, but you're iounmap'ing before freeing
irq. Looks fishy to me.
Br, David
> + }
> if (dev->irq_registered)
> free_irq(pdev->irq, dev);
> - if (dev->regs)
> - iounmap(dev->regs);
> if (dev->mem_region)
> release_mem_region(pci_resource_start(pdev, 0),
> pci_resource_len(pdev, 0));
> --
> 1.9.1
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference
2015-09-10 18:03 ` David Cohen
@ 2015-09-11 10:02 ` Sudip Mukherjee
2015-09-11 13:28 ` Felipe Balbi
0 siblings, 1 reply; 6+ messages in thread
From: Sudip Mukherjee @ 2015-09-11 10:02 UTC (permalink / raw)
To: David Cohen
Cc: Thomas Dahlmann, Felipe Balbi, Greg Kroah-Hartman, linux-kernel,
linux-geode, linux-usb
On Thu, Sep 10, 2015 at 11:03:34AM -0700, David Cohen wrote:
> Hi Sudip,
>
> On Fri, Sep 04, 2015 at 05:12:23PM +0530, Sudip Mukherjee wrote:
> > We were checking if dev->regs is NULL but it was done after
> > dereferencing it. Lets reset the controller and iounmap dev->regs only
> > if it is not NULL.
> > free_irq() does not need dev->regs, so unmaping it before freeing the
> > irq should not matter.
> >
> > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> > ---
> > drivers/usb/gadget/udc/amd5536udc.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
> > index fdacddb..26066d3 100644
> > --- a/drivers/usb/gadget/udc/amd5536udc.c
> > +++ b/drivers/usb/gadget/udc/amd5536udc.c
> > @@ -3135,11 +3135,12 @@ static void udc_pci_remove(struct pci_dev *pdev)
<snip>
>
> I'm not familiar with the driver, but you're iounmap'ing before freeing
> irq. Looks fishy to me.
Well, I thought you will be able to give me some idea about how fix it. :)
Then I guess we should be on the safe side and what about the following:
diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
index fdacddb..82f36f6 100644
--- a/drivers/usb/gadget/udc/amd5536udc.c
+++ b/drivers/usb/gadget/udc/amd5536udc.c
@@ -3134,8 +3134,9 @@ static void udc_pci_remove(struct pci_dev *pdev)
pci_pool_destroy(dev->stp_requests);
}
- /* reset controller */
- writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
+ if (dev->regs)
+ /* reset controller */
+ writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
if (dev->irq_registered)
free_irq(pdev->irq, dev);
if (dev->regs)
And just for my information: for a device what might happen if I iounmap
before I free the irq? One thing I can think of is that after iounmap
just at that moment one interrupt comes and the driver tries to access
the io memory while servicing the irq.
regards
sudip
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference
2015-09-11 10:02 ` Sudip Mukherjee
@ 2015-09-11 13:28 ` Felipe Balbi
2015-09-11 14:21 ` Sudip Mukherjee
0 siblings, 1 reply; 6+ messages in thread
From: Felipe Balbi @ 2015-09-11 13:28 UTC (permalink / raw)
To: Sudip Mukherjee
Cc: David Cohen, Thomas Dahlmann, Felipe Balbi, Greg Kroah-Hartman,
linux-kernel, linux-geode, linux-usb
[-- Attachment #1: Type: text/plain, Size: 2965 bytes --]
Hi,
On Fri, Sep 11, 2015 at 03:32:56PM +0530, Sudip Mukherjee wrote:
> On Thu, Sep 10, 2015 at 11:03:34AM -0700, David Cohen wrote:
> > Hi Sudip,
> >
> > On Fri, Sep 04, 2015 at 05:12:23PM +0530, Sudip Mukherjee wrote:
> > > We were checking if dev->regs is NULL but it was done after
> > > dereferencing it. Lets reset the controller and iounmap dev->regs only
> > > if it is not NULL.
> > > free_irq() does not need dev->regs, so unmaping it before freeing the
> > > irq should not matter.
> > >
> > > Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
> > > ---
> > > drivers/usb/gadget/udc/amd5536udc.c | 7 ++++---
> > > 1 file changed, 4 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
> > > index fdacddb..26066d3 100644
> > > --- a/drivers/usb/gadget/udc/amd5536udc.c
> > > +++ b/drivers/usb/gadget/udc/amd5536udc.c
> > > @@ -3135,11 +3135,12 @@ static void udc_pci_remove(struct pci_dev *pdev)
> <snip>
> >
> > I'm not familiar with the driver, but you're iounmap'ing before freeing
> > irq. Looks fishy to me.
> Well, I thought you will be able to give me some idea about how fix it. :)
> Then I guess we should be on the safe side and what about the following:
>
>
> diff --git a/drivers/usb/gadget/udc/amd5536udc.c b/drivers/usb/gadget/udc/amd5536udc.c
> index fdacddb..82f36f6 100644
> --- a/drivers/usb/gadget/udc/amd5536udc.c
> +++ b/drivers/usb/gadget/udc/amd5536udc.c
> @@ -3134,8 +3134,9 @@ static void udc_pci_remove(struct pci_dev *pdev)
> pci_pool_destroy(dev->stp_requests);
> }
>
> - /* reset controller */
> - writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
> + if (dev->regs)
> + /* reset controller */
> + writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
no, the check is pointless. Most of these are. Just look at your probe()
and you'll see that if dev->virt_addr is NULL (meaning ioremap_nocache()
failed) you exit from probe() with error. The driver doesn't probe at
all. So you can be sure that by remove, dev->regs is valid.
BTW, if probe fails, you have a TON of leaked resources!! You don't kfree()
dev, you don't pci_disable_device(), you don't release_mem_region(), you
don't iounmap() virt_addr, you don't free_irq().
Also the iounmap() call in remove is wrong. You ioremapped
dev->virt_addr but iounmap() dev->regs. Are you SURE that's ok ?
Man, what a mess! You gotta fix that up.
> if (dev->irq_registered)
> free_irq(pdev->irq, dev);
> if (dev->regs)
>
> And just for my information: for a device what might happen if I iounmap
> before I free the irq? One thing I can think of is that after iounmap
what happens if an IRQ fires after you iounmap() but before you
free_irq() ?
> just at that moment one interrupt comes and the driver tries to access
> the io memory while servicing the irq.
there you go
--
balbi
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference
2015-09-11 13:28 ` Felipe Balbi
@ 2015-09-11 14:21 ` Sudip Mukherjee
2015-09-11 15:05 ` Felipe Balbi
0 siblings, 1 reply; 6+ messages in thread
From: Sudip Mukherjee @ 2015-09-11 14:21 UTC (permalink / raw)
To: Felipe Balbi
Cc: David Cohen, Thomas Dahlmann, Greg Kroah-Hartman, linux-kernel,
linux-geode, linux-usb
On Fri, Sep 11, 2015 at 08:28:34AM -0500, Felipe Balbi wrote:
> Hi,
>
> On Fri, Sep 11, 2015 at 03:32:56PM +0530, Sudip Mukherjee wrote:
> > On Thu, Sep 10, 2015 at 11:03:34AM -0700, David Cohen wrote:
<snip>
> no, the check is pointless. Most of these are. Just look at your probe()
> and you'll see that if dev->virt_addr is NULL (meaning ioremap_nocache()
> failed) you exit from probe() with error. The driver doesn't probe at
> all. So you can be sure that by remove, dev->regs is valid.
>
> BTW, if probe fails, you have a TON of leaked resources!! You don't kfree()
> dev, you don't pci_disable_device(), you don't release_mem_region(), you
> don't iounmap() virt_addr, you don't free_irq().
>
> Also the iounmap() call in remove is wrong. You ioremapped
> dev->virt_addr but iounmap() dev->regs. Are you SURE that's ok ?
>
> Man, what a mess! You gotta fix that up.
:(
Yes, total mess. I am on it.
BTW, while I am fixing it can i also include a patch which will
rearrange the functions and remove the forward declarations?
regards
sudip
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference
2015-09-11 14:21 ` Sudip Mukherjee
@ 2015-09-11 15:05 ` Felipe Balbi
0 siblings, 0 replies; 6+ messages in thread
From: Felipe Balbi @ 2015-09-11 15:05 UTC (permalink / raw)
To: Sudip Mukherjee
Cc: Felipe Balbi, David Cohen, Thomas Dahlmann, Greg Kroah-Hartman,
linux-kernel, linux-geode, linux-usb
[-- Attachment #1: Type: text/plain, Size: 1300 bytes --]
On Fri, Sep 11, 2015 at 07:51:01PM +0530, Sudip Mukherjee wrote:
> On Fri, Sep 11, 2015 at 08:28:34AM -0500, Felipe Balbi wrote:
> > Hi,
> >
> > On Fri, Sep 11, 2015 at 03:32:56PM +0530, Sudip Mukherjee wrote:
> > > On Thu, Sep 10, 2015 at 11:03:34AM -0700, David Cohen wrote:
> <snip>
> > no, the check is pointless. Most of these are. Just look at your probe()
> > and you'll see that if dev->virt_addr is NULL (meaning ioremap_nocache()
> > failed) you exit from probe() with error. The driver doesn't probe at
> > all. So you can be sure that by remove, dev->regs is valid.
> >
> > BTW, if probe fails, you have a TON of leaked resources!! You don't kfree()
> > dev, you don't pci_disable_device(), you don't release_mem_region(), you
> > don't iounmap() virt_addr, you don't free_irq().
> >
> > Also the iounmap() call in remove is wrong. You ioremapped
> > dev->virt_addr but iounmap() dev->regs. Are you SURE that's ok ?
> >
> > Man, what a mess! You gotta fix that up.
> :(
> Yes, total mess. I am on it.
> BTW, while I am fixing it can i also include a patch which will
> rearrange the functions and remove the forward declarations?
sure, just make sure fixes and cleanups are separate. First all fixes,
then cleanups and reorderings.
cheers
--
balbi
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-09-11 15:05 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-09-04 11:42 [PATCH] usb: gadget: amd5536udc: fix NULL pointer dereference Sudip Mukherjee
2015-09-10 18:03 ` David Cohen
2015-09-11 10:02 ` Sudip Mukherjee
2015-09-11 13:28 ` Felipe Balbi
2015-09-11 14:21 ` Sudip Mukherjee
2015-09-11 15:05 ` Felipe Balbi
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