* [PATCH] Be a bit defensive in quirk_nvidia_ck804() so we don't risk dereferencing a NULL pdev.
@ 2006-12-01 23:21 Jesper Juhl
2006-12-01 23:55 ` Alan
2006-12-02 0:59 ` David Rientjes
0 siblings, 2 replies; 3+ messages in thread
From: Jesper Juhl @ 2006-12-01 23:21 UTC (permalink / raw)
To: linux-kernel; +Cc: Martin Mares
pci_get_slot() may return NULL if nothing was found.
quirk_nvidia_ck804() does not check the value returned from pci_get_slot(),
so it may end up causing a NULL pointer deref.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
---
drivers/pci/quirks.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 5b44838..d3dcbda 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1741,6 +1741,8 @@ static void __devinit quirk_nvidia_ck804
* a single one having MSI is enough to be sure that MSI are supported.
*/
pdev = pci_get_slot(dev->bus, 0);
+ if (!pdev)
+ return;
if (dev->subordinate && !msi_ht_cap_enabled(dev)
&& !msi_ht_cap_enabled(pdev)) {
printk(KERN_WARNING "PCI: MSI quirk detected. "
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Be a bit defensive in quirk_nvidia_ck804() so we don't risk dereferencing a NULL pdev.
2006-12-01 23:21 [PATCH] Be a bit defensive in quirk_nvidia_ck804() so we don't risk dereferencing a NULL pdev Jesper Juhl
@ 2006-12-01 23:55 ` Alan
2006-12-02 0:59 ` David Rientjes
1 sibling, 0 replies; 3+ messages in thread
From: Alan @ 2006-12-01 23:55 UTC (permalink / raw)
To: Jesper Juhl; +Cc: linux-kernel, Martin Mares
On Sat, 2 Dec 2006 00:21:56 +0100
Jesper Juhl <jesper.juhl@gmail.com> wrote:
> pci_get_slot() may return NULL if nothing was found.
> quirk_nvidia_ck804() does not check the value returned from pci_get_slot(),
> so it may end up causing a NULL pointer deref.
>
>
> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
I don't think its a physically possible case but it does no harm and
it'll kill boot if it happens
Acked-by: Alan Cox <alan@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Be a bit defensive in quirk_nvidia_ck804() so we don't risk dereferencing a NULL pdev.
2006-12-01 23:21 [PATCH] Be a bit defensive in quirk_nvidia_ck804() so we don't risk dereferencing a NULL pdev Jesper Juhl
2006-12-01 23:55 ` Alan
@ 2006-12-02 0:59 ` David Rientjes
1 sibling, 0 replies; 3+ messages in thread
From: David Rientjes @ 2006-12-02 0:59 UTC (permalink / raw)
To: Jesper Juhl; +Cc: linux-kernel, Martin Mares
On Sat, 2 Dec 2006, Jesper Juhl wrote:
> pci_get_slot() may return NULL if nothing was found.
> quirk_nvidia_ck804() does not check the value returned from pci_get_slot(),
> so it may end up causing a NULL pointer deref.
>
Looks good. The possible NULL pointer is actually not at pci_dev_put,
but rather at pci_find_capability on the msi_ht_cap_enabled(pdev) call.
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 5b44838..d3dcbda 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -1741,6 +1741,8 @@ static void __devinit quirk_nvidia_ck804
> * a single one having MSI is enough to be sure that MSI are supported.
> */
> pdev = pci_get_slot(dev->bus, 0);
> + if (!pdev)
> + return;
> if (dev->subordinate && !msi_ht_cap_enabled(dev)
> && !msi_ht_cap_enabled(pdev)) {
> printk(KERN_WARNING "PCI: MSI quirk detected. "
>
The check for dev->subordinate in the neighboring conditional can also be
removed.
David
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2006-12-02 1:00 UTC | newest]
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2006-12-01 23:55 ` Alan
2006-12-02 0:59 ` David Rientjes
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