* [PATCH] usb: rtl8150: avoid using uninitialized CSCR value
@ 2026-04-02 7:07 Morduan Zang
2026-04-02 15:51 ` Petko Manolov
2026-04-03 15:45 ` Simon Horman
0 siblings, 2 replies; 5+ messages in thread
From: Morduan Zang @ 2026-04-02 7:07 UTC (permalink / raw)
To: Petko Manolov
Cc: Andrew Lunn, David S . Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, linux-usb, netdev, linux-kernel,
syzbot+9db6c624635564ad813c, Morduan Zang
Check get_registers() when reading CSCR in set_carrier().
If the control transfer fails, don't use the stack value.
Reported-by: syzbot+9db6c624635564ad813c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9db6c624635564ad813c
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Morduan Zang <zhangdandan@uniontech.com>
---
drivers/net/usb/rtl8150.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
index 4cda0643afb6..7e32726d3e6f 100644
--- a/drivers/net/usb/rtl8150.c
+++ b/drivers/net/usb/rtl8150.c
@@ -722,7 +722,11 @@ static void set_carrier(struct net_device *netdev)
rtl8150_t *dev = netdev_priv(netdev);
short tmp;
- get_registers(dev, CSCR, 2, &tmp);
+ if (get_registers(dev, CSCR, 2, &tmp) < 0) {
+ netif_carrier_off(netdev);
+ return;
+ }
+
if (tmp & CSCR_LINK_STATUS)
netif_carrier_on(netdev);
else
--
2.50.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] usb: rtl8150: avoid using uninitialized CSCR value
2026-04-02 7:07 [PATCH] usb: rtl8150: avoid using uninitialized CSCR value Morduan Zang
@ 2026-04-02 15:51 ` Petko Manolov
2026-04-03 15:45 ` Simon Horman
1 sibling, 0 replies; 5+ messages in thread
From: Petko Manolov @ 2026-04-02 15:51 UTC (permalink / raw)
To: Morduan Zang
Cc: Andrew Lunn, David S . Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, linux-usb, netdev, linux-kernel,
syzbot+9db6c624635564ad813c
On 26-04-02 15:07:43, Morduan Zang wrote:
> Check get_registers() when reading CSCR in set_carrier().
> If the control transfer fails, don't use the stack value.
>
> Reported-by: syzbot+9db6c624635564ad813c@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=9db6c624635564ad813c
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Morduan Zang <zhangdandan@uniontech.com>
> ---
> drivers/net/usb/rtl8150.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
> index 4cda0643afb6..7e32726d3e6f 100644
> --- a/drivers/net/usb/rtl8150.c
> +++ b/drivers/net/usb/rtl8150.c
> @@ -722,7 +722,11 @@ static void set_carrier(struct net_device *netdev)
> rtl8150_t *dev = netdev_priv(netdev);
> short tmp;
>
> - get_registers(dev, CSCR, 2, &tmp);
> + if (get_registers(dev, CSCR, 2, &tmp) < 0) {
> + netif_carrier_off(netdev);
> + return;
> + }
> +
> if (tmp & CSCR_LINK_STATUS)
> netif_carrier_on(netdev);
> else
> --
Nice catch. You can add my Acked-by.
cheers,
Petko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] usb: rtl8150: avoid using uninitialized CSCR value
2026-04-02 7:07 [PATCH] usb: rtl8150: avoid using uninitialized CSCR value Morduan Zang
2026-04-02 15:51 ` Petko Manolov
@ 2026-04-03 15:45 ` Simon Horman
2026-04-05 8:52 ` Petko Manolov
1 sibling, 1 reply; 5+ messages in thread
From: Simon Horman @ 2026-04-03 15:45 UTC (permalink / raw)
To: Morduan Zang
Cc: Petko Manolov, Andrew Lunn, David S . Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, linux-usb, netdev, linux-kernel,
syzbot+9db6c624635564ad813c
On Thu, Apr 02, 2026 at 03:07:43PM +0800, Morduan Zang wrote:
> Check get_registers() when reading CSCR in set_carrier().
> If the control transfer fails, don't use the stack value.
>
> Reported-by: syzbot+9db6c624635564ad813c@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=9db6c624635564ad813c
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Morduan Zang <zhangdandan@uniontech.com>
> ---
> drivers/net/usb/rtl8150.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
> index 4cda0643afb6..7e32726d3e6f 100644
> --- a/drivers/net/usb/rtl8150.c
> +++ b/drivers/net/usb/rtl8150.c
> @@ -722,7 +722,11 @@ static void set_carrier(struct net_device *netdev)
> rtl8150_t *dev = netdev_priv(netdev);
> short tmp;
>
> - get_registers(dev, CSCR, 2, &tmp);
> + if (get_registers(dev, CSCR, 2, &tmp) < 0) {
> + netif_carrier_off(netdev);
> + return;
> + }
> +
> if (tmp & CSCR_LINK_STATUS)
> netif_carrier_on(netdev);
> else
I wonder if we can handle this a bit more succinctly,
while still making it clear that the error is handled.
Something like this:
diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
index 4cda0643afb6..816759ced56c 100644
--- a/drivers/net/usb/rtl8150.c
+++ b/drivers/net/usb/rtl8150.c
@@ -722,7 +722,8 @@ static void set_carrier(struct net_device *netdev)
rtl8150_t *dev = netdev_priv(netdev);
short tmp;
- get_registers(dev, CSCR, 2, &tmp);
+ if (get_registers(dev, CSCR, 2, &tmp) < 0)
+ tmp = 0;
if (tmp & CSCR_LINK_STATUS)
netif_carrier_on(netdev);
else
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] usb: rtl8150: avoid using uninitialized CSCR value
2026-04-03 15:45 ` Simon Horman
@ 2026-04-05 8:52 ` Petko Manolov
2026-04-05 23:38 ` Andrew Lunn
0 siblings, 1 reply; 5+ messages in thread
From: Petko Manolov @ 2026-04-05 8:52 UTC (permalink / raw)
To: Simon Horman
Cc: Morduan Zang, Andrew Lunn, David S . Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, linux-usb, netdev, linux-kernel,
syzbot+9db6c624635564ad813c
On 26-04-03 16:45:38, Simon Horman wrote:
> On Thu, Apr 02, 2026 at 03:07:43PM +0800, Morduan Zang wrote:
> > Check get_registers() when reading CSCR in set_carrier().
> > If the control transfer fails, don't use the stack value.
> >
> > Reported-by: syzbot+9db6c624635564ad813c@syzkaller.appspotmail.com
> > Closes: https://syzkaller.appspot.com/bug?extid=9db6c624635564ad813c
> > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> > Signed-off-by: Morduan Zang <zhangdandan@uniontech.com>
> > ---
> > drivers/net/usb/rtl8150.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
> > index 4cda0643afb6..7e32726d3e6f 100644
> > --- a/drivers/net/usb/rtl8150.c
> > +++ b/drivers/net/usb/rtl8150.c
> > @@ -722,7 +722,11 @@ static void set_carrier(struct net_device *netdev)
> > rtl8150_t *dev = netdev_priv(netdev);
> > short tmp;
> >
> > - get_registers(dev, CSCR, 2, &tmp);
> > + if (get_registers(dev, CSCR, 2, &tmp) < 0) {
> > + netif_carrier_off(netdev);
> > + return;
> > + }
> > +
> > if (tmp & CSCR_LINK_STATUS)
> > netif_carrier_on(netdev);
> > else
>
> I wonder if we can handle this a bit more succinctly,
> while still making it clear that the error is handled.
> Something like this:
>
> diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
> index 4cda0643afb6..816759ced56c 100644
> --- a/drivers/net/usb/rtl8150.c
> +++ b/drivers/net/usb/rtl8150.c
> @@ -722,7 +722,8 @@ static void set_carrier(struct net_device *netdev)
> rtl8150_t *dev = netdev_priv(netdev);
> short tmp;
>
> - get_registers(dev, CSCR, 2, &tmp);
> + if (get_registers(dev, CSCR, 2, &tmp) < 0)
> + tmp = 0;
> if (tmp & CSCR_LINK_STATUS)
> netif_carrier_on(netdev);
> else
I was wondering if calling netif_carrier_off() is the right thing to do in case
get_registers() fail.
There are multiple get_registers() calls that don't check the error and if we do
this in set_carrier() maybe we should do the same thing across the whole driver?
cheers,
Petko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] usb: rtl8150: avoid using uninitialized CSCR value
2026-04-05 8:52 ` Petko Manolov
@ 2026-04-05 23:38 ` Andrew Lunn
0 siblings, 0 replies; 5+ messages in thread
From: Andrew Lunn @ 2026-04-05 23:38 UTC (permalink / raw)
To: Petko Manolov
Cc: Simon Horman, Morduan Zang, Andrew Lunn, David S . Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-usb, netdev,
linux-kernel, syzbot+9db6c624635564ad813c
> > - get_registers(dev, CSCR, 2, &tmp);
> > + if (get_registers(dev, CSCR, 2, &tmp) < 0)
> > + tmp = 0;
> > if (tmp & CSCR_LINK_STATUS)
> > netif_carrier_on(netdev);
> > else
>
> I was wondering if calling netif_carrier_off() is the right thing to do in case
> get_registers() fail.
>
> There are multiple get_registers() calls that don't check the error and if we do
> this in set_carrier() maybe we should do the same thing across the whole driver?
What does it actually mean if get_registers() fails? The device is
gone? Hot unplugged? If so, you are going to get a cascade of errors,
and then hopefully the USB core code removes the device?
Are there any legitimate reasons for get_registers() to fail if the
device is still plugged in?
It seems netif_carrier_off() is unnecessary?
Andrew
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2026-04-05 23:38 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2026-04-02 7:07 [PATCH] usb: rtl8150: avoid using uninitialized CSCR value Morduan Zang
2026-04-02 15:51 ` Petko Manolov
2026-04-03 15:45 ` Simon Horman
2026-04-05 8:52 ` Petko Manolov
2026-04-05 23:38 ` Andrew Lunn
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