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* [PATCH] udmabuf: validate ubuf->pagecount
@ 2021-12-30 14:26 ` Pavel Skripkin
  0 siblings, 0 replies; 8+ messages in thread
From: Pavel Skripkin @ 2021-12-30 14:26 UTC (permalink / raw)
  To: kraxel, sumit.semwal, christian.koenig, daniel.vetter
  Cc: dri-devel, linux-media, linaro-mm-sig, linux-kernel,
	Pavel Skripkin, syzbot+2c56b725ec547fa9cb29

Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
problem was in ubuf->pages == ZERO_PTR.

ubuf->pagecount is calculated from arguments passed from user-space. If
user creates udmabuf with list.size == 0 then ubuf->pagecount will be
also equal to zero; it causes kmalloc_array() to return ZERO_PTR.

Fix it by validating ubuf->pagecount before passing it to
kmalloc_array().

Fixes: fbb0de795078 ("Add udmabuf misc device")
Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---

Happy New Year and Merry Christmas! :)


With regards,
Pavel Skripkin

---
 drivers/dma-buf/udmabuf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index c57a609db75b..e7330684d3b8 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device,
 		if (ubuf->pagecount > pglimit)
 			goto err;
 	}
+
+	if (!ubuf->pagecount)
+		goto err;
+
 	ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
 				    GFP_KERNEL);
 	if (!ubuf->pages) {
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH] udmabuf: validate ubuf->pagecount
@ 2021-12-30 14:26 ` Pavel Skripkin
  0 siblings, 0 replies; 8+ messages in thread
From: Pavel Skripkin @ 2021-12-30 14:26 UTC (permalink / raw)
  To: kraxel, sumit.semwal, christian.koenig, daniel.vetter
  Cc: Pavel Skripkin, linux-kernel, dri-devel, linaro-mm-sig,
	syzbot+2c56b725ec547fa9cb29, linux-media

Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
problem was in ubuf->pages == ZERO_PTR.

ubuf->pagecount is calculated from arguments passed from user-space. If
user creates udmabuf with list.size == 0 then ubuf->pagecount will be
also equal to zero; it causes kmalloc_array() to return ZERO_PTR.

Fix it by validating ubuf->pagecount before passing it to
kmalloc_array().

Fixes: fbb0de795078 ("Add udmabuf misc device")
Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---

Happy New Year and Merry Christmas! :)


With regards,
Pavel Skripkin

---
 drivers/dma-buf/udmabuf.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index c57a609db75b..e7330684d3b8 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device,
 		if (ubuf->pagecount > pglimit)
 			goto err;
 	}
+
+	if (!ubuf->pagecount)
+		goto err;
+
 	ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
 				    GFP_KERNEL);
 	if (!ubuf->pages) {
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH] udmabuf: validate ubuf->pagecount
  2021-12-30 14:26 ` Pavel Skripkin
@ 2022-01-12 18:08   ` Pavel Skripkin
  -1 siblings, 0 replies; 8+ messages in thread
From: Pavel Skripkin @ 2022-01-12 18:08 UTC (permalink / raw)
  To: kraxel, sumit.semwal, christian.koenig, daniel.vetter
  Cc: linaro-mm-sig, syzbot+2c56b725ec547fa9cb29, linux-kernel,
	dri-devel, linux-media

On 12/30/21 17:26, Pavel Skripkin wrote:
> Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
> problem was in ubuf->pages == ZERO_PTR.
> 
> ubuf->pagecount is calculated from arguments passed from user-space. If
> user creates udmabuf with list.size == 0 then ubuf->pagecount will be
> also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
> 
> Fix it by validating ubuf->pagecount before passing it to
> kmalloc_array().
> 
> Fixes: fbb0de795078 ("Add udmabuf misc device")
> Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> ---
> 

Gentle ping :)

> 
> ---
>   drivers/dma-buf/udmabuf.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
> index c57a609db75b..e7330684d3b8 100644
> --- a/drivers/dma-buf/udmabuf.c
> +++ b/drivers/dma-buf/udmabuf.c
> @@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device,
>   		if (ubuf->pagecount > pglimit)
>   			goto err;
>   	}
> +
> +	if (!ubuf->pagecount)
> +		goto err;
> +
>   	ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
>   				    GFP_KERNEL);
>   	if (!ubuf->pages) {

With regards,
Pavel Skripkin

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] udmabuf: validate ubuf->pagecount
@ 2022-01-12 18:08   ` Pavel Skripkin
  0 siblings, 0 replies; 8+ messages in thread
From: Pavel Skripkin @ 2022-01-12 18:08 UTC (permalink / raw)
  To: kraxel, sumit.semwal, christian.koenig, daniel.vetter
  Cc: dri-devel, linux-media, linaro-mm-sig, linux-kernel,
	syzbot+2c56b725ec547fa9cb29

On 12/30/21 17:26, Pavel Skripkin wrote:
> Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
> problem was in ubuf->pages == ZERO_PTR.
> 
> ubuf->pagecount is calculated from arguments passed from user-space. If
> user creates udmabuf with list.size == 0 then ubuf->pagecount will be
> also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
> 
> Fix it by validating ubuf->pagecount before passing it to
> kmalloc_array().
> 
> Fixes: fbb0de795078 ("Add udmabuf misc device")
> Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> ---
> 

Gentle ping :)

> 
> ---
>   drivers/dma-buf/udmabuf.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
> index c57a609db75b..e7330684d3b8 100644
> --- a/drivers/dma-buf/udmabuf.c
> +++ b/drivers/dma-buf/udmabuf.c
> @@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device,
>   		if (ubuf->pagecount > pglimit)
>   			goto err;
>   	}
> +
> +	if (!ubuf->pagecount)
> +		goto err;
> +
>   	ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
>   				    GFP_KERNEL);
>   	if (!ubuf->pages) {

With regards,
Pavel Skripkin

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] udmabuf: validate ubuf->pagecount
  2022-01-12 18:08   ` Pavel Skripkin
@ 2022-01-14 16:57     ` Daniel Vetter
  -1 siblings, 0 replies; 8+ messages in thread
From: Daniel Vetter @ 2022-01-14 16:57 UTC (permalink / raw)
  To: Pavel Skripkin
  Cc: kraxel, sumit.semwal, christian.koenig, daniel.vetter, dri-devel,
	linux-media, linaro-mm-sig, linux-kernel,
	syzbot+2c56b725ec547fa9cb29

On Wed, Jan 12, 2022 at 09:08:46PM +0300, Pavel Skripkin wrote:
> On 12/30/21 17:26, Pavel Skripkin wrote:
> > Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
> > problem was in ubuf->pages == ZERO_PTR.
> > 
> > ubuf->pagecount is calculated from arguments passed from user-space. If
> > user creates udmabuf with list.size == 0 then ubuf->pagecount will be
> > also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
> > 
> > Fix it by validating ubuf->pagecount before passing it to
> > kmalloc_array().
> > 
> > Fixes: fbb0de795078 ("Add udmabuf misc device")
> > Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
> > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> > ---
> > 
> 
> Gentle ping :)

Gerd Hoffmann should pick this one up, pls holler again if it doesn't
happen.
-Daniel

> 
> > 
> > ---
> >   drivers/dma-buf/udmabuf.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
> > index c57a609db75b..e7330684d3b8 100644
> > --- a/drivers/dma-buf/udmabuf.c
> > +++ b/drivers/dma-buf/udmabuf.c
> > @@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device,
> >   		if (ubuf->pagecount > pglimit)
> >   			goto err;
> >   	}
> > +
> > +	if (!ubuf->pagecount)
> > +		goto err;
> > +
> >   	ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
> >   				    GFP_KERNEL);
> >   	if (!ubuf->pages) {
> 
> With regards,
> Pavel Skripkin

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] udmabuf: validate ubuf->pagecount
@ 2022-01-14 16:57     ` Daniel Vetter
  0 siblings, 0 replies; 8+ messages in thread
From: Daniel Vetter @ 2022-01-14 16:57 UTC (permalink / raw)
  To: Pavel Skripkin
  Cc: daniel.vetter, linux-kernel, dri-devel, linaro-mm-sig, kraxel,
	syzbot+2c56b725ec547fa9cb29, christian.koenig, linux-media

On Wed, Jan 12, 2022 at 09:08:46PM +0300, Pavel Skripkin wrote:
> On 12/30/21 17:26, Pavel Skripkin wrote:
> > Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
> > problem was in ubuf->pages == ZERO_PTR.
> > 
> > ubuf->pagecount is calculated from arguments passed from user-space. If
> > user creates udmabuf with list.size == 0 then ubuf->pagecount will be
> > also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
> > 
> > Fix it by validating ubuf->pagecount before passing it to
> > kmalloc_array().
> > 
> > Fixes: fbb0de795078 ("Add udmabuf misc device")
> > Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
> > Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> > ---
> > 
> 
> Gentle ping :)

Gerd Hoffmann should pick this one up, pls holler again if it doesn't
happen.
-Daniel

> 
> > 
> > ---
> >   drivers/dma-buf/udmabuf.c | 4 ++++
> >   1 file changed, 4 insertions(+)
> > 
> > diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
> > index c57a609db75b..e7330684d3b8 100644
> > --- a/drivers/dma-buf/udmabuf.c
> > +++ b/drivers/dma-buf/udmabuf.c
> > @@ -190,6 +190,10 @@ static long udmabuf_create(struct miscdevice *device,
> >   		if (ubuf->pagecount > pglimit)
> >   			goto err;
> >   	}
> > +
> > +	if (!ubuf->pagecount)
> > +		goto err;
> > +
> >   	ubuf->pages = kmalloc_array(ubuf->pagecount, sizeof(*ubuf->pages),
> >   				    GFP_KERNEL);
> >   	if (!ubuf->pages) {
> 
> With regards,
> Pavel Skripkin

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] udmabuf: validate ubuf->pagecount
  2021-12-30 14:26 ` Pavel Skripkin
@ 2022-01-18  6:56   ` Gerd Hoffmann
  -1 siblings, 0 replies; 8+ messages in thread
From: Gerd Hoffmann @ 2022-01-18  6:56 UTC (permalink / raw)
  To: Pavel Skripkin
  Cc: daniel.vetter, linux-kernel, dri-devel, christian.koenig,
	linaro-mm-sig, syzbot+2c56b725ec547fa9cb29, linux-media

On Thu, Dec 30, 2021 at 05:26:49PM +0300, Pavel Skripkin wrote:
> Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
> problem was in ubuf->pages == ZERO_PTR.
> 
> ubuf->pagecount is calculated from arguments passed from user-space. If
> user creates udmabuf with list.size == 0 then ubuf->pagecount will be
> also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
> 
> Fix it by validating ubuf->pagecount before passing it to
> kmalloc_array().
> 
> Fixes: fbb0de795078 ("Add udmabuf misc device")
> Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> ---

Pushed to drm-misc-next.

thanks,
  Gerd


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] udmabuf: validate ubuf->pagecount
@ 2022-01-18  6:56   ` Gerd Hoffmann
  0 siblings, 0 replies; 8+ messages in thread
From: Gerd Hoffmann @ 2022-01-18  6:56 UTC (permalink / raw)
  To: Pavel Skripkin
  Cc: sumit.semwal, christian.koenig, daniel.vetter, dri-devel,
	linux-media, linaro-mm-sig, linux-kernel,
	syzbot+2c56b725ec547fa9cb29

On Thu, Dec 30, 2021 at 05:26:49PM +0300, Pavel Skripkin wrote:
> Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The
> problem was in ubuf->pages == ZERO_PTR.
> 
> ubuf->pagecount is calculated from arguments passed from user-space. If
> user creates udmabuf with list.size == 0 then ubuf->pagecount will be
> also equal to zero; it causes kmalloc_array() to return ZERO_PTR.
> 
> Fix it by validating ubuf->pagecount before passing it to
> kmalloc_array().
> 
> Fixes: fbb0de795078 ("Add udmabuf misc device")
> Reported-and-tested-by: syzbot+2c56b725ec547fa9cb29@syzkaller.appspotmail.com
> Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
> ---

Pushed to drm-misc-next.

thanks,
  Gerd


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2022-01-18  6:57 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-12-30 14:26 [PATCH] udmabuf: validate ubuf->pagecount Pavel Skripkin
2021-12-30 14:26 ` Pavel Skripkin
2022-01-12 18:08 ` Pavel Skripkin
2022-01-12 18:08   ` Pavel Skripkin
2022-01-14 16:57   ` Daniel Vetter
2022-01-14 16:57     ` Daniel Vetter
2022-01-18  6:56 ` Gerd Hoffmann
2022-01-18  6:56   ` Gerd Hoffmann

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