* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-19 5:06 [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject Wang Hai
@ 2019-03-18 15:57 ` Stephen Hemminger
2019-03-18 16:19 ` Andy Shevchenko
2019-03-19 3:03 ` wanghai (M)
2019-03-18 18:02 ` Eric Dumazet
1 sibling, 2 replies; 12+ messages in thread
From: Stephen Hemminger @ 2019-03-18 15:57 UTC (permalink / raw)
To: Wang Hai
Cc: davem, idosch, alexander.h.duyck, tyhicks, f.fainelli,
amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel
On Tue, 19 Mar 2019 01:06:57 -0400
Wang Hai <wanghai26@huawei.com> wrote:
> When registering struct net_device, it will call
> register_netdevice ->
> netdev_register_kobject ->
> device_add(dev)
> register_queue_kobjects(ndev)
>
> If device_add(dev) or register_queue_kobjects(ndev) fails.
> Register_netdevice() will return error, causing netdev_freemem(ndev)
> to be called to free net_device, however (&ndev->dev)->kobj.name will
> not be freed, resulting in a memory leak.
>
> syzkaller report this:
> BUG: memory leak
> unreferenced object 0xffff8881f4fad168 (size 8):
> comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
> hex dump (first 8 bytes):
> 77 70 61 6e 30 00 ff ff wpan0...
> backtrace:
> [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
> [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
> [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
> [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
> [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
> [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
> [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
> [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
> [<00000000e4b3df51>] 0xffffffffc1500e0e
> [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
> [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
> [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
> [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
> [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
> [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
> [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
> Signed-off-by: Wang Hai <wanghai26@huawei.com>
> ---
> net/core/net-sysfs.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index 4ff661f..f0e53dc 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev)
>
> error = device_add(dev);
> if (error)
> - return error;
> + goto device_add_error;
>
> error = register_queue_kobjects(ndev);
> - if (error) {
> - device_del(dev);
> - return error;
> - }
> + if (error)
> + goto register_error;
>
> pm_runtime_set_memalloc_noio(dev, true);
>
> +out:
> return error;
> +
> +register_error:
> + device_del(dev);
> +device_add_error:
> + kfree_const(dev->kobj.name);
This looks a bug in device_add() not here.
In general, it is better for an api to clean up after itself.
Since dev->kobj.name is created in device_add and normally freed
in device_del; why is device_add leaving it behind?
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-18 15:57 ` Stephen Hemminger
@ 2019-03-18 16:19 ` Andy Shevchenko
[not found] ` <c1c266af-7aaa-00a7-aa7a-e61c65665741@huawei.com>
2019-03-19 3:03 ` wanghai (M)
1 sibling, 1 reply; 12+ messages in thread
From: Andy Shevchenko @ 2019-03-18 16:19 UTC (permalink / raw)
To: Stephen Hemminger
Cc: Wang Hai, davem, idosch, alexander.h.duyck, tyhicks, f.fainelli,
amritha.nambiar, joe, dmitry.torokhov, netdev, linux-kernel
On Mon, Mar 18, 2019 at 08:57:24AM -0700, Stephen Hemminger wrote:
> On Tue, 19 Mar 2019 01:06:57 -0400
> Wang Hai <wanghai26@huawei.com> wrote:
>
> > When registering struct net_device, it will call
> > register_netdevice ->
> > netdev_register_kobject ->
> > device_add(dev)
> > register_queue_kobjects(ndev)
> >
> > If device_add(dev) or register_queue_kobjects(ndev) fails.
> > Register_netdevice() will return error, causing netdev_freemem(ndev)
> > to be called to free net_device, however (&ndev->dev)->kobj.name will
> > not be freed, resulting in a memory leak.
> >
> > syzkaller report this:
> > BUG: memory leak
> > unreferenced object 0xffff8881f4fad168 (size 8):
> > comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
> > hex dump (first 8 bytes):
> > 77 70 61 6e 30 00 ff ff wpan0...
> > backtrace:
> > [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
> > [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
> > [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
> > [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
> > [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
> > [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
> > [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
> > [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
> > [<00000000e4b3df51>] 0xffffffffc1500e0e
> > [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
> > [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
> > [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
> > [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
> > [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
> > [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
> > [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
> >
> > Reported-by: Hulk Robot <hulkci@huawei.com>
> > Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
> > Signed-off-by: Wang Hai <wanghai26@huawei.com>
> > ---
> > net/core/net-sysfs.c | 15 ++++++++++-----
> > 1 file changed, 10 insertions(+), 5 deletions(-)
> >
> > diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> > index 4ff661f..f0e53dc 100644
> > --- a/net/core/net-sysfs.c
> > +++ b/net/core/net-sysfs.c
> > @@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev)
> >
> > error = device_add(dev);
> > if (error)
> > - return error;
> > + goto device_add_error;
> >
> > error = register_queue_kobjects(ndev);
> > - if (error) {
> > - device_del(dev);
> > - return error;
> > - }
> > + if (error)
> > + goto register_error;
> >
> > pm_runtime_set_memalloc_noio(dev, true);
> >
> > +out:
> > return error;
> > +
> > +register_error:
> > + device_del(dev);
> > +device_add_error:
> > + kfree_const(dev->kobj.name);
>
> This looks a bug in device_add() not here.
> In general, it is better for an api to clean up after itself.
> Since dev->kobj.name is created in device_add and normally freed
> in device_del; why is device_add leaving it behind?
It's more likely the bug in syzkaller.
Look at the kobject_cleanup() last lines of code...
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-19 5:06 [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject Wang Hai
2019-03-18 15:57 ` Stephen Hemminger
@ 2019-03-18 18:02 ` Eric Dumazet
2019-03-19 3:47 ` wanghai (M)
1 sibling, 1 reply; 12+ messages in thread
From: Eric Dumazet @ 2019-03-18 18:02 UTC (permalink / raw)
To: Wang Hai, davem, idosch, alexander.h.duyck, tyhicks, f.fainelli
Cc: amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel
On 03/18/2019 10:06 PM, Wang Hai wrote:
> When registering struct net_device, it will call
> register_netdevice ->
> netdev_register_kobject ->
> device_add(dev)
> register_queue_kobjects(ndev)
>
> If device_add(dev) or register_queue_kobjects(ndev) fails.
> Register_netdevice() will return error, causing netdev_freemem(ndev)
> to be called to free net_device, however (&ndev->dev)->kobj.name will
> not be freed, resulting in a memory leak.
>
> syzkaller report this:
> BUG: memory leak
> unreferenced object 0xffff8881f4fad168 (size 8):
> comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
> hex dump (first 8 bytes):
> 77 70 61 6e 30 00 ff ff wpan0...
> backtrace:
> [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
> [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
> [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
> [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
> [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
> [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
> [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
> [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
> [<00000000e4b3df51>] 0xffffffffc1500e0e
> [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
> [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
> [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
> [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
> [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
> [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
> [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
>
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
The bug was there before this commit, right ?
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-18 15:57 ` Stephen Hemminger
2019-03-18 16:19 ` Andy Shevchenko
@ 2019-03-19 3:03 ` wanghai (M)
2019-03-19 3:15 ` Stephen Hemminger
1 sibling, 1 reply; 12+ messages in thread
From: wanghai (M) @ 2019-03-19 3:03 UTC (permalink / raw)
To: Stephen Hemminger
Cc: davem, idosch, alexander.h.duyck, tyhicks, f.fainelli,
amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel
在 2019/3/18 23:57, Stephen Hemminger 写道:
> On Tue, 19 Mar 2019 01:06:57 -0400
> Wang Hai <wanghai26@huawei.com> wrote:
>
>> When registering struct net_device, it will call
>> register_netdevice ->
>> netdev_register_kobject ->
>> device_add(dev)
>> register_queue_kobjects(ndev)
>>
>> If device_add(dev) or register_queue_kobjects(ndev) fails.
>> Register_netdevice() will return error, causing netdev_freemem(ndev)
>> to be called to free net_device, however (&ndev->dev)->kobj.name will
>> not be freed, resulting in a memory leak.
>>
>> syzkaller report this:
>> BUG: memory leak
>> unreferenced object 0xffff8881f4fad168 (size 8):
>> comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
>> hex dump (first 8 bytes):
>> 77 70 61 6e 30 00 ff ff wpan0...
>> backtrace:
>> [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
>> [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
>> [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
>> [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
>> [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
>> [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
>> [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
>> [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
>> [<00000000e4b3df51>] 0xffffffffc1500e0e
>> [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
>> [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
>> [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
>> [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
>> [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
>> [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
>> [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
>> Signed-off-by: Wang Hai <wanghai26@huawei.com>
>> ---
>> net/core/net-sysfs.c | 15 ++++++++++-----
>> 1 file changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
>> index 4ff661f..f0e53dc 100644
>> --- a/net/core/net-sysfs.c
>> +++ b/net/core/net-sysfs.c
>> @@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev)
>>
>> error = device_add(dev);
>> if (error)
>> - return error;
>> + goto device_add_error;
>>
>> error = register_queue_kobjects(ndev);
>> - if (error) {
>> - device_del(dev);
>> - return error;
>> - }
>> + if (error)
>> + goto register_error;
>>
>> pm_runtime_set_memalloc_noio(dev, true);
>>
>> +out:
>> return error;
>> +
>> +register_error:
>> + device_del(dev);
>> +device_add_error:
>> + kfree_const(dev->kobj.name);
> This looks a bug in device_add() not here.
> In general, it is better for an api to clean up after itself.
> Since dev->kobj.name is created in device_add and normally freed
> in device_del; why is device_add leaving it behind?\
When registering struct net_device, it will call
register_netdevice ->
netdev_register_kobject ->
dev_set_name(dev, "%s", ndev->name)
device_add(dev)
register_queue_kobjects(ndev)
The dev->kobj.name that causes the memory leak is created in
dev_set_name(dev, "%s", ndev-> name) in the function
netdev_register_kobject(), not in device_add(dev). If device_add(dev) or
register_queue_kobjects(ndev) fails, it should release dev-> kobj.name
in netdev_register_kobject()
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-19 3:03 ` wanghai (M)
@ 2019-03-19 3:15 ` Stephen Hemminger
2019-03-19 3:39 ` wanghai (M)
0 siblings, 1 reply; 12+ messages in thread
From: Stephen Hemminger @ 2019-03-19 3:15 UTC (permalink / raw)
To: wanghai (M)
Cc: davem, idosch, alexander.h.duyck, tyhicks, f.fainelli,
amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel
On Tue, 19 Mar 2019 11:03:54 +0800
"wanghai (M)" <wanghai26@huawei.com> wrote:
> 在 2019/3/18 23:57, Stephen Hemminger 写道:
> > On Tue, 19 Mar 2019 01:06:57 -0400
> > Wang Hai <wanghai26@huawei.com> wrote:
> >
> >> When registering struct net_device, it will call
> >> register_netdevice ->
> >> netdev_register_kobject ->
> >> device_add(dev)
> >> register_queue_kobjects(ndev)
> >>
> >> If device_add(dev) or register_queue_kobjects(ndev) fails.
> >> Register_netdevice() will return error, causing netdev_freemem(ndev)
> >> to be called to free net_device, however (&ndev->dev)->kobj.name will
> >> not be freed, resulting in a memory leak.
> >>
> >> syzkaller report this:
> >> BUG: memory leak
> >> unreferenced object 0xffff8881f4fad168 (size 8):
> >> comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
> >> hex dump (first 8 bytes):
> >> 77 70 61 6e 30 00 ff ff wpan0...
> >> backtrace:
> >> [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
> >> [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
> >> [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
> >> [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
> >> [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
> >> [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
> >> [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
> >> [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
> >> [<00000000e4b3df51>] 0xffffffffc1500e0e
> >> [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
> >> [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
> >> [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
> >> [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
> >> [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
> >> [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
> >> [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
> >>
> >> Reported-by: Hulk Robot <hulkci@huawei.com>
> >> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
> >> Signed-off-by: Wang Hai <wanghai26@huawei.com>
> >> ---
> >> net/core/net-sysfs.c | 15 ++++++++++-----
> >> 1 file changed, 10 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> >> index 4ff661f..f0e53dc 100644
> >> --- a/net/core/net-sysfs.c
> >> +++ b/net/core/net-sysfs.c
> >> @@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev)
> >>
> >> error = device_add(dev);
> >> if (error)
> >> - return error;
> >> + goto device_add_error;
> >>
> >> error = register_queue_kobjects(ndev);
> >> - if (error) {
> >> - device_del(dev);
> >> - return error;
> >> - }
> >> + if (error)
> >> + goto register_error;
> >>
> >> pm_runtime_set_memalloc_noio(dev, true);
> >>
> >> +out:
> >> return error;
> >> +
> >> +register_error:
> >> + device_del(dev);
> >> +device_add_error:
> >> + kfree_const(dev->kobj.name);
> > This looks a bug in device_add() not here.
> > In general, it is better for an api to clean up after itself.
> > Since dev->kobj.name is created in device_add and normally freed
> > in device_del; why is device_add leaving it behind?\
>
> When registering struct net_device, it will call
> register_netdevice ->
> netdev_register_kobject ->
> dev_set_name(dev, "%s", ndev->name)
> device_add(dev)
> register_queue_kobjects(ndev)
>
> The dev->kobj.name that causes the memory leak is created in
> dev_set_name(dev, "%s", ndev-> name) in the function
> netdev_register_kobject(), not in device_add(dev). If device_add(dev) or
> register_queue_kobjects(ndev) fails, it should release dev-> kobj.name
> in netdev_register_kobject()
Good catch, dev_set_name is using asprintf to allocate new memory
for the name. The problem with your patch is that device_del()
already cleans up the device (including name). The device object
should really not be touched after device_del.
Where is the name freed in the normal case?
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-19 3:15 ` Stephen Hemminger
@ 2019-03-19 3:39 ` wanghai (M)
2019-03-19 10:22 ` Andy Shevchenko
0 siblings, 1 reply; 12+ messages in thread
From: wanghai (M) @ 2019-03-19 3:39 UTC (permalink / raw)
To: Stephen Hemminger
Cc: davem, idosch, alexander.h.duyck, tyhicks, f.fainelli,
amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel
在 2019/3/19 11:15, Stephen Hemminger 写道:
> On Tue, 19 Mar 2019 11:03:54 +0800
> "wanghai (M)" <wanghai26@huawei.com> wrote:
>
>> 在 2019/3/18 23:57, Stephen Hemminger 写道:
>>> On Tue, 19 Mar 2019 01:06:57 -0400
>>> Wang Hai <wanghai26@huawei.com> wrote:
>>>
>>>> When registering struct net_device, it will call
>>>> register_netdevice ->
>>>> netdev_register_kobject ->
>>>> device_add(dev)
>>>> register_queue_kobjects(ndev)
>>>>
>>>> If device_add(dev) or register_queue_kobjects(ndev) fails.
>>>> Register_netdevice() will return error, causing netdev_freemem(ndev)
>>>> to be called to free net_device, however (&ndev->dev)->kobj.name will
>>>> not be freed, resulting in a memory leak.
>>>>
>>>> syzkaller report this:
>>>> BUG: memory leak
>>>> unreferenced object 0xffff8881f4fad168 (size 8):
>>>> comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
>>>> hex dump (first 8 bytes):
>>>> 77 70 61 6e 30 00 ff ff wpan0...
>>>> backtrace:
>>>> [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
>>>> [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
>>>> [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
>>>> [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
>>>> [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
>>>> [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
>>>> [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
>>>> [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
>>>> [<00000000e4b3df51>] 0xffffffffc1500e0e
>>>> [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
>>>> [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
>>>> [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
>>>> [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
>>>> [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
>>>> [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
>>>> [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
>>>>
>>>> Reported-by: Hulk Robot <hulkci@huawei.com>
>>>> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
>>>> Signed-off-by: Wang Hai <wanghai26@huawei.com>
>>>> ---
>>>> net/core/net-sysfs.c | 15 ++++++++++-----
>>>> 1 file changed, 10 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
>>>> index 4ff661f..f0e53dc 100644
>>>> --- a/net/core/net-sysfs.c
>>>> +++ b/net/core/net-sysfs.c
>>>> @@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev)
>>>>
>>>> error = device_add(dev);
>>>> if (error)
>>>> - return error;
>>>> + goto device_add_error;
>>>>
>>>> error = register_queue_kobjects(ndev);
>>>> - if (error) {
>>>> - device_del(dev);
>>>> - return error;
>>>> - }
>>>> + if (error)
>>>> + goto register_error;
>>>>
>>>> pm_runtime_set_memalloc_noio(dev, true);
>>>>
>>>> +out:
>>>> return error;
>>>> +
>>>> +register_error:
>>>> + device_del(dev);
>>>> +device_add_error:
>>>> + kfree_const(dev->kobj.name);
>>> This looks a bug in device_add() not here.
>>> In general, it is better for an api to clean up after itself.
>>> Since dev->kobj.name is created in device_add and normally freed
>>> in device_del; why is device_add leaving it behind?\
>> When registering struct net_device, it will call
>> register_netdevice ->
>> netdev_register_kobject ->
>> dev_set_name(dev, "%s", ndev->name)
>> device_add(dev)
>> register_queue_kobjects(ndev)
>>
>> The dev->kobj.name that causes the memory leak is created in
>> dev_set_name(dev, "%s", ndev-> name) in the function
>> netdev_register_kobject(), not in device_add(dev). If device_add(dev) or
>> register_queue_kobjects(ndev) fails, it should release dev-> kobj.name
>> in netdev_register_kobject()
> Good catch, dev_set_name is using asprintf to allocate new memory
> for the name. The problem with your patch is that device_del()
> already cleans up the device (including name). The device object
> should really not be touched after device_del.
>
> Where is the name freed in the normal case?
>
>
> .
Device_del just delete device from system, but do not clean up
dev->kobj.name. In normal case, the name is freed in
free_netdev(dev)->put_device(&dev->dev)->kobject_put(&dev->kobj)->kobject_cleanup()
,not in device_del()
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-18 18:02 ` Eric Dumazet
@ 2019-03-19 3:47 ` wanghai (M)
0 siblings, 0 replies; 12+ messages in thread
From: wanghai (M) @ 2019-03-19 3:47 UTC (permalink / raw)
To: Eric Dumazet, davem, idosch, alexander.h.duyck, tyhicks, f.fainelli
Cc: amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel
在 2019/3/19 2:02, Eric Dumazet 写道:
>
> On 03/18/2019 10:06 PM, Wang Hai wrote:
>> When registering struct net_device, it will call
>> register_netdevice ->
>> netdev_register_kobject ->
>> device_add(dev)
>> register_queue_kobjects(ndev)
>>
>> If device_add(dev) or register_queue_kobjects(ndev) fails.
>> Register_netdevice() will return error, causing netdev_freemem(ndev)
>> to be called to free net_device, however (&ndev->dev)->kobj.name will
>> not be freed, resulting in a memory leak.
>>
>> syzkaller report this:
>> BUG: memory leak
>> unreferenced object 0xffff8881f4fad168 (size 8):
>> comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
>> hex dump (first 8 bytes):
>> 77 70 61 6e 30 00 ff ff wpan0...
>> backtrace:
>> [<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
>> [<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
>> [<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
>> [<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
>> [<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
>> [<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
>> [<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
>> [<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
>> [<00000000e4b3df51>] 0xffffffffc1500e0e
>> [<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
>> [<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
>> [<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
>> [<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
>> [<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
>> [<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
>> [<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
>>
>> Reported-by: Hulk Robot <hulkci@huawei.com>
>> Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
> The bug was there before this commit, right ?
>
> .
Sorry, I read the code carefully, this is a mistake, the correct fix commit is 1fa5ae857bb1(driver core: get rid of struct device's bus_id string array). I will send a patch v2
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
@ 2019-03-19 5:06 Wang Hai
2019-03-18 15:57 ` Stephen Hemminger
2019-03-18 18:02 ` Eric Dumazet
0 siblings, 2 replies; 12+ messages in thread
From: Wang Hai @ 2019-03-19 5:06 UTC (permalink / raw)
To: davem, idosch, alexander.h.duyck, tyhicks, f.fainelli
Cc: amritha.nambiar, joe, dmitry.torokhov, andriy.shevchenko, netdev,
linux-kernel, wanghai26
When registering struct net_device, it will call
register_netdevice ->
netdev_register_kobject ->
device_add(dev)
register_queue_kobjects(ndev)
If device_add(dev) or register_queue_kobjects(ndev) fails.
Register_netdevice() will return error, causing netdev_freemem(ndev)
to be called to free net_device, however (&ndev->dev)->kobj.name will
not be freed, resulting in a memory leak.
syzkaller report this:
BUG: memory leak
unreferenced object 0xffff8881f4fad168 (size 8):
comm "syz-executor.0", pid 3575, jiffies 4294778002 (age 20.134s)
hex dump (first 8 bytes):
77 70 61 6e 30 00 ff ff wpan0...
backtrace:
[<000000006d2d91d7>] kstrdup_const+0x3d/0x50 mm/util.c:73
[<00000000ba9ff953>] kvasprintf_const+0x112/0x170 lib/kasprintf.c:48
[<000000005555ec09>] kobject_set_name_vargs+0x55/0x130 lib/kobject.c:281
[<0000000098d28ec3>] dev_set_name+0xbb/0xf0 drivers/base/core.c:1915
[<00000000b7553017>] netdev_register_kobject+0xc0/0x410 net/core/net-sysfs.c:1727
[<00000000c826a797>] register_netdevice+0xa51/0xeb0 net/core/dev.c:8711
[<00000000857bfcfd>] cfg802154_update_iface_num.isra.2+0x13/0x90 [ieee802154]
[<000000003126e453>] ieee802154_llsec_fill_key_id+0x1d5/0x570 [ieee802154]
[<00000000e4b3df51>] 0xffffffffc1500e0e
[<00000000b4319776>] platform_drv_probe+0xc6/0x180 drivers/base/platform.c:614
[<0000000037669347>] really_probe+0x491/0x7c0 drivers/base/dd.c:509
[<000000008fed8862>] driver_probe_device+0xdc/0x240 drivers/base/dd.c:671
[<00000000baf52041>] device_driver_attach+0xf2/0x130 drivers/base/dd.c:945
[<00000000c7cc8dec>] __driver_attach+0x10e/0x210 drivers/base/dd.c:1022
[<0000000057a757c2>] bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
[<000000005f5ae04b>] bus_add_driver+0x427/0x5e0 drivers/base/bus.c:645
Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: 1d24eb4815d1 ("xps: Transmit Packet Steering")
Signed-off-by: Wang Hai <wanghai26@huawei.com>
---
net/core/net-sysfs.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 4ff661f..f0e53dc 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1745,17 +1745,22 @@ int netdev_register_kobject(struct net_device *ndev)
error = device_add(dev);
if (error)
- return error;
+ goto device_add_error;
error = register_queue_kobjects(ndev);
- if (error) {
- device_del(dev);
- return error;
- }
+ if (error)
+ goto register_error;
pm_runtime_set_memalloc_noio(dev, true);
+out:
return error;
+
+register_error:
+ device_del(dev);
+device_add_error:
+ kfree_const(dev->kobj.name);
+ goto out;
}
int netdev_class_create_file_ns(const struct class_attribute *class_attr,
--
1.8.3.1
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
2019-03-19 3:39 ` wanghai (M)
@ 2019-03-19 10:22 ` Andy Shevchenko
0 siblings, 0 replies; 12+ messages in thread
From: Andy Shevchenko @ 2019-03-19 10:22 UTC (permalink / raw)
To: wanghai (M)
Cc: Stephen Hemminger, davem, idosch, alexander.h.duyck, tyhicks,
f.fainelli, amritha.nambiar, joe, dmitry.torokhov, netdev,
linux-kernel
On Tue, Mar 19, 2019 at 11:39:54AM +0800, wanghai (M) wrote:
> 在 2019/3/19 11:15, Stephen Hemminger 写道:
> Device_del just delete device from system, but do not clean up
> dev->kobj.name.
May I ask how you get this conclusion?
> In normal case, the name is freed in free_netdev(dev)->put_device(&dev->dev)->kobject_put(&dev->kobj)->kobject_cleanup()
> ,not in device_del()
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
[not found] ` <c1c266af-7aaa-00a7-aa7a-e61c65665741@huawei.com>
@ 2019-03-19 10:30 ` Andy Shevchenko
[not found] ` <18553079-7bbd-fcfe-ef1c-6717e963e0a5@huawei.com>
0 siblings, 1 reply; 12+ messages in thread
From: Andy Shevchenko @ 2019-03-19 10:30 UTC (permalink / raw)
To: wanghai (M)
Cc: Stephen Hemminger, davem, idosch, alexander.h.duyck, tyhicks,
f.fainelli, amritha.nambiar, joe, dmitry.torokhov, netdev,
linux-kernel
On Tue, Mar 19, 2019 at 11:19:24AM +0800, wanghai (M) wrote:
>
> 在 2019/3/19 0:19, Andy Shevchenko 写道:
> > On Mon, Mar 18, 2019 at 08:57:24AM -0700, Stephen Hemminger wrote:
> > > On Tue, 19 Mar 2019 01:06:57 -0400
> > > Wang Hai <wanghai26@huawei.com> wrote:
> > > This looks a bug in device_add() not here.
> > > In general, it is better for an api to clean up after itself.
> > > Since dev->kobj.name is created in device_add and normally freed
> > > in device_del; why is device_add leaving it behind?
> > It's more likely the bug in syzkaller.
> >
> > Look at the kobject_cleanup() last lines of code...
> If device_add(dev) or register_queue_kobjects(ndev) fails,
> In register_netdevice(), dev-> reg_state = NETREG_UNINITIALIZED and returns
> an error, causing put_device(&dev-> dev) -> ..-> kobject_cleanup() not to be
> called.
OK, that's true, but your patch is wrong.
See error handling in device_create_groups_vargs() for example.
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
[not found] ` <18553079-7bbd-fcfe-ef1c-6717e963e0a5@huawei.com>
@ 2019-03-19 14:00 ` Andy Shevchenko
2019-03-19 15:44 ` Stephen Hemminger
1 sibling, 0 replies; 12+ messages in thread
From: Andy Shevchenko @ 2019-03-19 14:00 UTC (permalink / raw)
To: wanghai (M)
Cc: Stephen Hemminger, davem, idosch, alexander.h.duyck, tyhicks,
f.fainelli, amritha.nambiar, joe, dmitry.torokhov, netdev,
linux-kernel
On Tue, Mar 19, 2019 at 08:17:01PM +0800, wanghai (M) wrote:
> 在 2019/3/19 18:30, Andy Shevchenko 写道:
> > On Tue, Mar 19, 2019 at 11:19:24AM +0800, wanghai (M) wrote:
> > > 在 2019/3/19 0:19, Andy Shevchenko 写道:
> > > If device_add(dev) or register_queue_kobjects(ndev) fails,
> > > In register_netdevice(), dev-> reg_state = NETREG_UNINITIALIZED and returns
> > > an error, causing put_device(&dev-> dev) -> ..-> kobject_cleanup() not to be
> > > called.
> > OK, that's true, but your patch is wrong.
> > See error handling in device_create_groups_vargs() for example.
> Hi Andy
> Thanks for your advice. I understand the problem of my patch.
> Can you help me see if it can be fixed like this?
>
> diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
> index 4ff661f..6fe5b8e 100644
> --- a/net/core/net-sysfs.c
> +++ b/net/core/net-sysfs.c
> @@ -1745,17 +1745,21 @@ int netdev_register_kobject(struct net_device *ndev)
>
> error = device_add(dev);
> if (error)
> - return error;
> + goto device_add_error;
This part seems correct now.
> error = register_queue_kobjects(ndev);
> - if (error) {
> - device_del(dev);
> - return error;
> - }
> + if (error)
> + goto register_error;
Yes, seems correct order here, i.e. device_del() followed by put_device().
>
> pm_runtime_set_memalloc_noio(dev, true);
>
> +out:
Better
return 0;
> return error;
> +register_error:
Better to describe what you will do here, i.e.
error_device_del:
> + device_del(dev);
> +device_add_error:
Ditto.
error_put_device:
> + put_device(dev);
> + goto out;
Better
return error;
> }
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject
[not found] ` <18553079-7bbd-fcfe-ef1c-6717e963e0a5@huawei.com>
2019-03-19 14:00 ` Andy Shevchenko
@ 2019-03-19 15:44 ` Stephen Hemminger
1 sibling, 0 replies; 12+ messages in thread
From: Stephen Hemminger @ 2019-03-19 15:44 UTC (permalink / raw)
To: wanghai (M)
Cc: Andy Shevchenko, davem, idosch, alexander.h.duyck, tyhicks,
f.fainelli, amritha.nambiar, joe, dmitry.torokhov, netdev,
linux-kernel
On Tue, 19 Mar 2019 20:17:01 +0800
"wanghai (M)" <wanghai26@huawei.com> wrote:
> +out:
> return error;
> +register_error:
> + device_del(dev);
> +device_add_error:
> + put_device(dev);
> + goto out;
Everything looks fine, but I would redo the last part without
the last goto out. Using a goto back to single return reduces
readability.
if (error)
goto register_error;
pm_runtime_set_memalloc_noio(dev, true);
return 0;
register_error:
device_del(dev);
device_add_error:
put_device(dev);
return error;
^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2019-03-19 15:45 UTC | newest]
Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-19 5:06 [PATCH] net-sysfs: Fix memory leak in netdev_register_kobject Wang Hai
2019-03-18 15:57 ` Stephen Hemminger
2019-03-18 16:19 ` Andy Shevchenko
[not found] ` <c1c266af-7aaa-00a7-aa7a-e61c65665741@huawei.com>
2019-03-19 10:30 ` Andy Shevchenko
[not found] ` <18553079-7bbd-fcfe-ef1c-6717e963e0a5@huawei.com>
2019-03-19 14:00 ` Andy Shevchenko
2019-03-19 15:44 ` Stephen Hemminger
2019-03-19 3:03 ` wanghai (M)
2019-03-19 3:15 ` Stephen Hemminger
2019-03-19 3:39 ` wanghai (M)
2019-03-19 10:22 ` Andy Shevchenko
2019-03-18 18:02 ` Eric Dumazet
2019-03-19 3:47 ` wanghai (M)
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