* [PATCH] net: dsa: loop: Check for memory allocation failure
@ 2017-05-06 5:29 Christophe JAILLET
2017-05-06 14:45 ` Andrew Lunn
` (3 more replies)
0 siblings, 4 replies; 11+ messages in thread
From: Christophe JAILLET @ 2017-05-06 5:29 UTC (permalink / raw)
To: andrew, vivien.didelot, f.fainelli
Cc: netdev, linux-kernel, kernel-janitors, Christophe JAILLET
If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
Return -ENOMEM instead, as done for some other memory allocation just a
few lines above.
Fixes: 98cd1552ea27 ("net: dsa: Mock-up driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
drivers/net/dsa/dsa_loop.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/net/dsa/dsa_loop.c b/drivers/net/dsa/dsa_loop.c
index f0fc4de4fc9a..a19e1781e9bb 100644
--- a/drivers/net/dsa/dsa_loop.c
+++ b/drivers/net/dsa/dsa_loop.c
@@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
return -ENOMEM;
ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
+ if (!ps)
+ return -ENOMEM;
+
ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
if (!ps->netdev)
return -EPROBE_DEFER;
--
2.11.0
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-06 5:29 [PATCH] net: dsa: loop: Check for memory allocation failure Christophe JAILLET
@ 2017-05-06 14:45 ` Andrew Lunn
2017-05-07 23:22 ` Florian Fainelli
` (2 subsequent siblings)
3 siblings, 0 replies; 11+ messages in thread
From: Andrew Lunn @ 2017-05-06 14:45 UTC (permalink / raw)
To: Christophe JAILLET
Cc: vivien.didelot, f.fainelli, netdev, linux-kernel, kernel-janitors
On Sat, May 06, 2017 at 07:29:45AM +0200, Christophe JAILLET wrote:
> If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> Return -ENOMEM instead, as done for some other memory allocation just a
> few lines above.
>
> Fixes: 98cd1552ea27 ("net: dsa: Mock-up driver")
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Andrew
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-06 5:29 [PATCH] net: dsa: loop: Check for memory allocation failure Christophe JAILLET
2017-05-06 14:45 ` Andrew Lunn
@ 2017-05-07 23:22 ` Florian Fainelli
2017-05-08 12:05 ` David Laight
2017-05-08 19:01 ` David Miller
3 siblings, 0 replies; 11+ messages in thread
From: Florian Fainelli @ 2017-05-07 23:22 UTC (permalink / raw)
To: Christophe JAILLET, andrew, vivien.didelot
Cc: netdev, linux-kernel, kernel-janitors
Le 05/05/17 à 22:29, Christophe JAILLET a écrit :
> If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> Return -ENOMEM instead, as done for some other memory allocation just a
> few lines above.
>
> Fixes: 98cd1552ea27 ("net: dsa: Mock-up driver")
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
--
Florian
^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-06 5:29 [PATCH] net: dsa: loop: Check for memory allocation failure Christophe JAILLET
2017-05-06 14:45 ` Andrew Lunn
2017-05-07 23:22 ` Florian Fainelli
@ 2017-05-08 12:05 ` David Laight
2017-05-08 12:32 ` Julia Lawall
2017-05-08 19:01 ` David Miller
3 siblings, 1 reply; 11+ messages in thread
From: David Laight @ 2017-05-08 12:05 UTC (permalink / raw)
To: 'Christophe JAILLET', andrew, vivien.didelot, f.fainelli
Cc: netdev, linux-kernel, kernel-janitors
From: Christophe JAILLET
> Sent: 06 May 2017 06:30
> If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> Return -ENOMEM instead, as done for some other memory allocation just a
> few lines above.
...
> --- a/drivers/net/dsa/dsa_loop.c
> +++ b/drivers/net/dsa/dsa_loop.c
> @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
> return -ENOMEM;
>
> ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
> + if (!ps)
> + return -ENOMEM;
> +
> ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
> if (!ps->netdev)
> return -EPROBE_DEFER;
On the face if it this code leaks like a sieve.
David
^ permalink raw reply [flat|nested] 11+ messages in thread
* RE: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-08 12:05 ` David Laight
@ 2017-05-08 12:32 ` Julia Lawall
2017-05-08 17:44 ` Joe Perches
0 siblings, 1 reply; 11+ messages in thread
From: Julia Lawall @ 2017-05-08 12:32 UTC (permalink / raw)
To: David Laight
Cc: 'Christophe JAILLET',
andrew, vivien.didelot, f.fainelli, netdev, linux-kernel,
kernel-janitors
On Mon, 8 May 2017, David Laight wrote:
> From: Christophe JAILLET
> > Sent: 06 May 2017 06:30
> > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> > Return -ENOMEM instead, as done for some other memory allocation just a
> > few lines above.
> ...
> > --- a/drivers/net/dsa/dsa_loop.c
> > +++ b/drivers/net/dsa/dsa_loop.c
> > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
> > return -ENOMEM;
> >
> > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
> > + if (!ps)
> > + return -ENOMEM;
> > +
> > ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
> > if (!ps->netdev)
> > return -EPROBE_DEFER;
>
> On the face if it this code leaks like a sieve.
I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use
devm functions.
julia
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-08 12:32 ` Julia Lawall
@ 2017-05-08 17:44 ` Joe Perches
2017-05-08 23:46 ` Julia Lawall
0 siblings, 1 reply; 11+ messages in thread
From: Joe Perches @ 2017-05-08 17:44 UTC (permalink / raw)
To: Julia Lawall, David Laight
Cc: 'Christophe JAILLET',
andrew, vivien.didelot, f.fainelli, netdev, linux-kernel,
kernel-janitors
On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote:
>
> On Mon, 8 May 2017, David Laight wrote:
>
> > From: Christophe JAILLET
> > > Sent: 06 May 2017 06:30
> > > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> > > Return -ENOMEM instead, as done for some other memory allocation just a
> > > few lines above.
> >
> > ...
> > > --- a/drivers/net/dsa/dsa_loop.c
> > > +++ b/drivers/net/dsa/dsa_loop.c
> > > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
> > > return -ENOMEM;
> > >
> > > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
> > > + if (!ps)
> > > + return -ENOMEM;
> > > +
> > > ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
> > > if (!ps->netdev)
> > > return -EPROBE_DEFER;
> >
> > On the face if it this code leaks like a sieve.
>
> I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use
> devm functions.
It's at least wasteful.
Each time -EPROBE_DEFER occurs, another set of calls to
dsa_switch_alloc and dev_kzalloc also occurs.
Perhaps it'd be better to do:
if (ps->netdev) {
devm_kfree(&devmdev->dev, ps);
devm_kfree(&mdiodev->dev, ds);
return -EPROBE_DEFER;
}
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-06 5:29 [PATCH] net: dsa: loop: Check for memory allocation failure Christophe JAILLET
` (2 preceding siblings ...)
2017-05-08 12:05 ` David Laight
@ 2017-05-08 19:01 ` David Miller
3 siblings, 0 replies; 11+ messages in thread
From: David Miller @ 2017-05-08 19:01 UTC (permalink / raw)
To: christophe.jaillet
Cc: andrew, vivien.didelot, f.fainelli, netdev, linux-kernel,
kernel-janitors
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Date: Sat, 6 May 2017 07:29:45 +0200
> If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> Return -ENOMEM instead, as done for some other memory allocation just a
> few lines above.
>
> Fixes: 98cd1552ea27 ("net: dsa: Mock-up driver")
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Please do not separate "Fixes: " tags from signoffs and acks with
empty lines in the future, thank you.
Applied and queued up for -stable.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-08 17:44 ` Joe Perches
@ 2017-05-08 23:46 ` Julia Lawall
2017-05-09 0:35 ` Florian Fainelli
0 siblings, 1 reply; 11+ messages in thread
From: Julia Lawall @ 2017-05-08 23:46 UTC (permalink / raw)
To: Joe Perches
Cc: David Laight, 'Christophe JAILLET',
andrew, vivien.didelot, f.fainelli, netdev, linux-kernel,
kernel-janitors
On Mon, 8 May 2017, Joe Perches wrote:
> On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote:
> >
> > On Mon, 8 May 2017, David Laight wrote:
> >
> > > From: Christophe JAILLET
> > > > Sent: 06 May 2017 06:30
> > > > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> > > > Return -ENOMEM instead, as done for some other memory allocation just a
> > > > few lines above.
> > >
> > > ...
> > > > --- a/drivers/net/dsa/dsa_loop.c
> > > > +++ b/drivers/net/dsa/dsa_loop.c
> > > > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
> > > > return -ENOMEM;
> > > >
> > > > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
> > > > + if (!ps)
> > > > + return -ENOMEM;
> > > > +
> > > > ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
> > > > if (!ps->netdev)
> > > > return -EPROBE_DEFER;
> > >
> > > On the face if it this code leaks like a sieve.
> >
> > I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use
> > devm functions.
>
> It's at least wasteful.
>
> Each time -EPROBE_DEFER occurs, another set of calls to
> dsa_switch_alloc and dev_kzalloc also occurs.
>
> Perhaps it'd be better to do:
>
> if (ps->netdev) {
> devm_kfree(&devmdev->dev, ps);
> devm_kfree(&mdiodev->dev, ds);
> return -EPROBE_DEFER;
> }
Is EPROBE_DEFER handled differently than other kinds of errors?
julia
>
> --
> To unsubscribe from this list: send the line "unsubscribe kernel-janitors" 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] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-08 23:46 ` Julia Lawall
@ 2017-05-09 0:35 ` Florian Fainelli
2017-05-09 0:39 ` Julia Lawall
2017-05-09 15:18 ` Joe Perches
0 siblings, 2 replies; 11+ messages in thread
From: Florian Fainelli @ 2017-05-09 0:35 UTC (permalink / raw)
To: Julia Lawall, Joe Perches
Cc: David Laight, 'Christophe JAILLET',
andrew, vivien.didelot, netdev, linux-kernel, kernel-janitors
On 05/08/2017 04:46 PM, Julia Lawall wrote:
>
>
> On Mon, 8 May 2017, Joe Perches wrote:
>
>> On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote:
>>>
>>> On Mon, 8 May 2017, David Laight wrote:
>>>
>>>> From: Christophe JAILLET
>>>>> Sent: 06 May 2017 06:30
>>>>> If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
>>>>> Return -ENOMEM instead, as done for some other memory allocation just a
>>>>> few lines above.
>>>>
>>>> ...
>>>>> --- a/drivers/net/dsa/dsa_loop.c
>>>>> +++ b/drivers/net/dsa/dsa_loop.c
>>>>> @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
>>>>> return -ENOMEM;
>>>>>
>>>>> ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
>>>>> + if (!ps)
>>>>> + return -ENOMEM;
>>>>> +
>>>>> ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
>>>>> if (!ps->netdev)
>>>>> return -EPROBE_DEFER;
>>>>
>>>> On the face if it this code leaks like a sieve.
>>>
>>> I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use
>>> devm functions.
>>
>> It's at least wasteful.
>>
>> Each time -EPROBE_DEFER occurs, another set of calls to
>> dsa_switch_alloc and dev_kzalloc also occurs.
>>
>> Perhaps it'd be better to do:
>>
>> if (ps->netdev) {
>> devm_kfree(&devmdev->dev, ps);
>> devm_kfree(&mdiodev->dev, ds);
>> return -EPROBE_DEFER;
>> }
>
> Is EPROBE_DEFER handled differently than other kinds of errors?
In the core device driver model, yes, EPROBE_DEFER is treated
differently than other errors because it puts the driver on a retry queue.
EPROBE_DEFER is already a slow and exceptional path, and this is a
mock-up driver, so I am not sure what value there is in trying to
balance devm_kzalloc() with corresponding devm_kfree()...
--
Florian
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-09 0:35 ` Florian Fainelli
@ 2017-05-09 0:39 ` Julia Lawall
2017-05-09 15:18 ` Joe Perches
1 sibling, 0 replies; 11+ messages in thread
From: Julia Lawall @ 2017-05-09 0:39 UTC (permalink / raw)
To: Florian Fainelli
Cc: Joe Perches, David Laight, 'Christophe JAILLET',
andrew, vivien.didelot, netdev, linux-kernel, kernel-janitors
On Mon, 8 May 2017, Florian Fainelli wrote:
> On 05/08/2017 04:46 PM, Julia Lawall wrote:
> >
> >
> > On Mon, 8 May 2017, Joe Perches wrote:
> >
> >> On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote:
> >>>
> >>> On Mon, 8 May 2017, David Laight wrote:
> >>>
> >>>> From: Christophe JAILLET
> >>>>> Sent: 06 May 2017 06:30
> >>>>> If 'devm_kzalloc' fails, a NULL pointer will be dereferenced.
> >>>>> Return -ENOMEM instead, as done for some other memory allocation just a
> >>>>> few lines above.
> >>>>
> >>>> ...
> >>>>> --- a/drivers/net/dsa/dsa_loop.c
> >>>>> +++ b/drivers/net/dsa/dsa_loop.c
> >>>>> @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev)
> >>>>> return -ENOMEM;
> >>>>>
> >>>>> ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL);
> >>>>> + if (!ps)
> >>>>> + return -ENOMEM;
> >>>>> +
> >>>>> ps->netdev = dev_get_by_name(&init_net, pdata->netdev);
> >>>>> if (!ps->netdev)
> >>>>> return -EPROBE_DEFER;
> >>>>
> >>>> On the face if it this code leaks like a sieve.
> >>>
> >>> I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use
> >>> devm functions.
> >>
> >> It's at least wasteful.
> >>
> >> Each time -EPROBE_DEFER occurs, another set of calls to
> >> dsa_switch_alloc and dev_kzalloc also occurs.
> >>
> >> Perhaps it'd be better to do:
> >>
> >> if (ps->netdev) {
> >> devm_kfree(&devmdev->dev, ps);
> >> devm_kfree(&mdiodev->dev, ds);
> >> return -EPROBE_DEFER;
> >> }
> >
> > Is EPROBE_DEFER handled differently than other kinds of errors?
>
> In the core device driver model, yes, EPROBE_DEFER is treated
> differently than other errors because it puts the driver on a retry queue.
>
> EPROBE_DEFER is already a slow and exceptional path, and this is a
> mock-up driver, so I am not sure what value there is in trying to
> balance devm_kzalloc() with corresponding devm_kfree()...
OK, thanks for the explanation.
julia
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] net: dsa: loop: Check for memory allocation failure
2017-05-09 0:35 ` Florian Fainelli
2017-05-09 0:39 ` Julia Lawall
@ 2017-05-09 15:18 ` Joe Perches
1 sibling, 0 replies; 11+ messages in thread
From: Joe Perches @ 2017-05-09 15:18 UTC (permalink / raw)
To: Florian Fainelli, Julia Lawall
Cc: David Laight, 'Christophe JAILLET',
andrew, vivien.didelot, netdev, linux-kernel, kernel-janitors
On Mon, 2017-05-08 at 17:35 -0700, Florian Fainelli wrote:
> On 05/08/2017 04:46 PM, Julia Lawall wrote:
> > On Mon, 8 May 2017, Joe Perches wrote:
> > > Each time -EPROBE_DEFER occurs, another set of calls to
> > > dsa_switch_alloc and dev_kzalloc also occurs.
> > >
> > > Perhaps it'd be better to do:
> > >
> > > if (ps->netdev) {
> > > devm_kfree(&devmdev->dev, ps);
> > > devm_kfree(&mdiodev->dev, ds);
> > > return -EPROBE_DEFER;
> > > }
> >
> > Is EPROBE_DEFER handled differently than other kinds of errors?
>
> In the core device driver model, yes, EPROBE_DEFER is treated
> differently than other errors because it puts the driver on a retry queue.
>
> EPROBE_DEFER is already a slow and exceptional path, and this is a
> mock-up driver, so I am not sure what value there is in trying to
> balance devm_kzalloc() with corresponding devm_kfree()...
Example code should be as correct as possible.
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2017-05-09 15:18 UTC | newest]
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2017-05-06 5:29 [PATCH] net: dsa: loop: Check for memory allocation failure Christophe JAILLET
2017-05-06 14:45 ` Andrew Lunn
2017-05-07 23:22 ` Florian Fainelli
2017-05-08 12:05 ` David Laight
2017-05-08 12:32 ` Julia Lawall
2017-05-08 17:44 ` Joe Perches
2017-05-08 23:46 ` Julia Lawall
2017-05-09 0:35 ` Florian Fainelli
2017-05-09 0:39 ` Julia Lawall
2017-05-09 15:18 ` Joe Perches
2017-05-08 19:01 ` David Miller
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