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* [BUG] media: cx88-alsa: Found a bug at the probe time
@ 2022-07-15  1:54 Zheyu Ma
  2022-07-16 19:03 ` Randy Dunlap
  0 siblings, 1 reply; 3+ messages in thread
From: Zheyu Ma @ 2022-07-15  1:54 UTC (permalink / raw)
  To: Mauro Carvalho Chehab; +Cc: linux-media, Linux Kernel Mailing List

Hello,

I found a bug in the driver cx88-alsa.

When the driver fails in the function snd_cx88_create() at the probe
time, it will cause a UAF bug as follows:

[   24.343899] Trying to free already-free IRQ 0
[   24.344815] WARNING: CPU: 7 PID: 389 at kernel/irq/manage.c:1895
free_irq+0x3a4/0x7c0
[   24.348448] RIP: 0010:free_irq+0x3a4/0x7c0
[   24.356716] Call Trace:
[   24.357124]  snd_cx88_dev_free+0x71/0x100 [cx88_alsa]
[   24.358008]  release_card_device+0x7d/0x190
[   24.358699]  device_release+0x97/0x1c0
[   24.359022]  kobject_put+0x144/0x1c0
[   24.359329]  snd_card_free+0xec/0x150
[   24.360078]  cx88_audio_initdev+0x8f4/0xce0 [cx88_alsa]

Since I'm not familiar with the driver, could you please give me some
hints to fix it?

regards,

Zheyu Ma

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [BUG] media: cx88-alsa: Found a bug at the probe time
  2022-07-15  1:54 [BUG] media: cx88-alsa: Found a bug at the probe time Zheyu Ma
@ 2022-07-16 19:03 ` Randy Dunlap
  2022-07-17  0:05   ` Zheyu Ma
  0 siblings, 1 reply; 3+ messages in thread
From: Randy Dunlap @ 2022-07-16 19:03 UTC (permalink / raw)
  To: Zheyu Ma, Mauro Carvalho Chehab; +Cc: linux-media, Linux Kernel Mailing List

Hi--

On 7/14/22 18:54, Zheyu Ma wrote:
> Hello,
> 
> I found a bug in the driver cx88-alsa.
> 
> When the driver fails in the function snd_cx88_create() at the probe
> time, it will cause a UAF bug as follows:

It's not a UAF. It's a WARN() macro with an IRQ management problem,
as shown in the next 2 lines below:
> 
> [   24.343899] Trying to free already-free IRQ 0
> [   24.344815] WARNING: CPU: 7 PID: 389 at kernel/irq/manage.c:1895
> free_irq+0x3a4/0x7c0
> [   24.348448] RIP: 0010:free_irq+0x3a4/0x7c0
> [   24.356716] Call Trace:
> [   24.357124]  snd_cx88_dev_free+0x71/0x100 [cx88_alsa]
> [   24.358008]  release_card_device+0x7d/0x190
> [   24.358699]  device_release+0x97/0x1c0
> [   24.359022]  kobject_put+0x144/0x1c0
> [   24.359329]  snd_card_free+0xec/0x150
> [   24.360078]  cx88_audio_initdev+0x8f4/0xce0 [cx88_alsa]
> 
> Since I'm not familiar with the driver, could you please give me some
> hints to fix it?
> 
> regards,
> 
> Zheyu Ma

-- 
~Randy

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [BUG] media: cx88-alsa: Found a bug at the probe time
  2022-07-16 19:03 ` Randy Dunlap
@ 2022-07-17  0:05   ` Zheyu Ma
  0 siblings, 0 replies; 3+ messages in thread
From: Zheyu Ma @ 2022-07-17  0:05 UTC (permalink / raw)
  To: Randy Dunlap
  Cc: Mauro Carvalho Chehab, linux-media, Linux Kernel Mailing List

On Sun, Jul 17, 2022 at 3:03 AM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> Hi--
>
> On 7/14/22 18:54, Zheyu Ma wrote:
> > Hello,
> >
> > I found a bug in the driver cx88-alsa.
> >
> > When the driver fails in the function snd_cx88_create() at the probe
> > time, it will cause a UAF bug as follows:
>
> It's not a UAF. It's a WARN() macro with an IRQ management problem,
> as shown in the next 2 lines below:

You are right, that is indeed just a warning :)

regards,

Zheyu Ma

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2022-07-17  0:05 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-07-15  1:54 [BUG] media: cx88-alsa: Found a bug at the probe time Zheyu Ma
2022-07-16 19:03 ` Randy Dunlap
2022-07-17  0:05   ` Zheyu Ma

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