2020-06-18 20:05:06

by Maciej Żenczykowski

Subject: [PATCH] restore behaviour of CAP_SYS_ADMIN allowing the loading of net bpf program

From: Maciej Żenczykowski <[email protected]>

This is a 5.8-rc1 regression.

Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
Signed-off-by: Maciej Żenczykowski <[email protected]>
---
kernel/bpf/syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8da159936bab..7d946435587d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2121,7 +2121,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
!bpf_capable())
return -EPERM;

- if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN))
+ if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
return -EPERM;
if (is_perfmon_prog_type(type) && !perfmon_capable())
return -EPERM;
--
2.27.0.290.gba653c62da-goog

2020-06-18 21:04:58

by Alexei Starovoitov

Subject: Re: [PATCH] restore behaviour of CAP_SYS_ADMIN allowing the loading of net bpf program

On Thu, Jun 18, 2020 at 1:00 PM Maciej Żenczykowski
<[email protected]> wrote:
>
> From: Maciej Żenczykowski <[email protected]>
>
> This is a 5.8-rc1 regression.

Please add full explanation here.

Also use [PATCH bpf] in the subject for future submission.

> Cc: Alexei Starovoitov <[email protected]>
> Cc: Daniel Borkmann <[email protected]>
> Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")

Reported-by: John
is missing?

> Signed-off-by: Maciej Żenczykowski <[email protected]>
> ---
> kernel/bpf/syscall.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> index 8da159936bab..7d946435587d 100644
> --- a/kernel/bpf/syscall.c
> +++ b/kernel/bpf/syscall.c
> @@ -2121,7 +2121,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
> !bpf_capable())
> return -EPERM;
>
> - if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN))
> + if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
> return -EPERM;
> if (is_perfmon_prog_type(type) && !perfmon_capable())
> return -EPERM;
> --
> 2.27.0.290.gba653c62da-goog
>

2020-06-20 21:29:56

by Maciej Żenczykowski

Subject: [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs

From: Maciej Żenczykowski <[email protected]>

This is a fix for a regression introduced in 5.8-rc1 by:
commit 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366
'bpf: Implement CAP_BPF'

Before the above commit it was possible to load network bpf programs
with just the CAP_SYS_ADMIN privilege.

The Android bpfloader happens to run in such a configuration (it has
SYS_ADMIN but not NET_ADMIN) and creates maps and loads bpf programs
for later use by Android's netd (which has NET_ADMIN but not SYS_ADMIN).

Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Reported-by: John Stultz <[email protected]>
Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
Signed-off-by: Maciej Żenczykowski <[email protected]>
---
kernel/bpf/syscall.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 8da159936bab..7d946435587d 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2121,7 +2121,7 @@ static int bpf_prog_load(union bpf_attr *attr, union bpf_attr __user *uattr)
!bpf_capable())
return -EPERM;

- if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN))
+ if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
return -EPERM;
if (is_perfmon_prog_type(type) && !perfmon_capable())
return -EPERM;
--
2.27.0.111.gc72c7da667-goog

2020-06-22 20:04:51

by John Stultz

Subject: Re: [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs

On Sat, Jun 20, 2020 at 2:26 PM Maciej Żenczykowski
<[email protected]> wrote:
>
> From: Maciej Żenczykowski <[email protected]>
>
> This is a fix for a regression introduced in 5.8-rc1 by:
> commit 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366
> 'bpf: Implement CAP_BPF'
>
> Before the above commit it was possible to load network bpf programs
> with just the CAP_SYS_ADMIN privilege.
>
> The Android bpfloader happens to run in such a configuration (it has
> SYS_ADMIN but not NET_ADMIN) and creates maps and loads bpf programs
> for later use by Android's netd (which has NET_ADMIN but not SYS_ADMIN).
>
> Cc: Alexei Starovoitov <[email protected]>
> Cc: Daniel Borkmann <[email protected]>
> Reported-by: John Stultz <[email protected]>
> Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
> Signed-off-by: Maciej Żenczykowski <[email protected]>

Thanks so much for helping narrow this regression down and submitting this fix!
It's much appreciated!

Tested-by: John Stultz <[email protected]>

thanks
-john

2020-06-24 00:55:30

by Alexei Starovoitov

Subject: Re: [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs

On Mon, Jun 22, 2020 at 12:44 PM John Stultz <[email protected]> wrote:
>
> On Sat, Jun 20, 2020 at 2:26 PM Maciej Żenczykowski
> <[email protected]> wrote:
> >
> > From: Maciej Żenczykowski <[email protected]>
> >
> > This is a fix for a regression introduced in 5.8-rc1 by:
> > commit 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366
> > 'bpf: Implement CAP_BPF'
> >
> > Before the above commit it was possible to load network bpf programs
> > with just the CAP_SYS_ADMIN privilege.
> >
> > The Android bpfloader happens to run in such a configuration (it has
> > SYS_ADMIN but not NET_ADMIN) and creates maps and loads bpf programs
> > for later use by Android's netd (which has NET_ADMIN but not SYS_ADMIN).
> >
> > Cc: Alexei Starovoitov <[email protected]>
> > Cc: Daniel Borkmann <[email protected]>
> > Reported-by: John Stultz <[email protected]>
> > Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
> > Signed-off-by: Maciej Żenczykowski <[email protected]>
>
> Thanks so much for helping narrow this regression down and submitting this fix!
> It's much appreciated!
>
> Tested-by: John Stultz <[email protected]>

Applied to bpf tree. Thanks

2020-07-06 20:12:38

by John Stultz

Subject: Re: [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs

On Tue, Jun 23, 2020 at 5:54 PM Alexei Starovoitov
<[email protected]> wrote:
> On Mon, Jun 22, 2020 at 12:44 PM John Stultz <[email protected]> wrote:
> > On Sat, Jun 20, 2020 at 2:26 PM Maciej Żenczykowski
> > <[email protected]> wrote:
> > > From: Maciej Żenczykowski <[email protected]>
> > >
> > > This is a fix for a regression introduced in 5.8-rc1 by:
> > > commit 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366
> > > 'bpf: Implement CAP_BPF'
> > >
> > > Before the above commit it was possible to load network bpf programs
> > > with just the CAP_SYS_ADMIN privilege.
> > >
> > > The Android bpfloader happens to run in such a configuration (it has
> > > SYS_ADMIN but not NET_ADMIN) and creates maps and loads bpf programs
> > > for later use by Android's netd (which has NET_ADMIN but not SYS_ADMIN).
> > >
> > > Cc: Alexei Starovoitov <[email protected]>
> > > Cc: Daniel Borkmann <[email protected]>
> > > Reported-by: John Stultz <[email protected]>
> > > Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
> > > Signed-off-by: Maciej Żenczykowski <[email protected]>
> >
> > Thanks so much for helping narrow this regression down and submitting this fix!
> > It's much appreciated!
> >
> > Tested-by: John Stultz <[email protected]>
>
> Applied to bpf tree. Thanks

Hey all,
Just wanted to follow up on this as I've not seen the regression fix
land in 5.8-rc4 yet? Is it still pending, or did it fall through a
gap?

thanks
-john

2020-07-06 20:16:34

by Daniel Borkmann

Subject: Re: [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs

On 7/6/20 10:11 PM, John Stultz wrote:
> On Tue, Jun 23, 2020 at 5:54 PM Alexei Starovoitov
> <[email protected]> wrote:
>> On Mon, Jun 22, 2020 at 12:44 PM John Stultz <[email protected]> wrote:
>>> On Sat, Jun 20, 2020 at 2:26 PM Maciej Żenczykowski
>>> <[email protected]> wrote:
>>>> From: Maciej Żenczykowski <[email protected]>
>>>>
>>>> This is a fix for a regression introduced in 5.8-rc1 by:
>>>> commit 2c78ee898d8f10ae6fb2fa23a3fbaec96b1b7366
>>>> 'bpf: Implement CAP_BPF'
>>>>
>>>> Before the above commit it was possible to load network bpf programs
>>>> with just the CAP_SYS_ADMIN privilege.
>>>>
>>>> The Android bpfloader happens to run in such a configuration (it has
>>>> SYS_ADMIN but not NET_ADMIN) and creates maps and loads bpf programs
>>>> for later use by Android's netd (which has NET_ADMIN but not SYS_ADMIN).
>>>>
>>>> Cc: Alexei Starovoitov <[email protected]>
>>>> Cc: Daniel Borkmann <[email protected]>
>>>> Reported-by: John Stultz <[email protected]>
>>>> Fixes: 2c78ee898d8f ("bpf: Implement CAP_BPF")
>>>> Signed-off-by: Maciej Żenczykowski <[email protected]>
>>>
>>> Thanks so much for helping narrow this regression down and submitting this fix!
>>> It's much appreciated!
>>>
>>> Tested-by: John Stultz <[email protected]>
>>
>> Applied to bpf tree. Thanks
>
> Hey all,
> Just wanted to follow up on this as I've not seen the regression fix
> land in 5.8-rc4 yet? Is it still pending, or did it fall through a
> gap?

No, it's in DaveM's -net tree currently, will go to Linus' tree on his next pull req:

https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b338cb921e6739ff59ce32f43342779fe5ffa732

2020-07-06 20:39:47

by John Stultz

Subject: Re: [PATCH bpf v2] restore behaviour of CAP_SYS_ADMIN allowing the loading of networking bpf programs

On Mon, Jul 6, 2020 at 1:15 PM Daniel Borkmann <[email protected]> wrote:
> On 7/6/20 10:11 PM, John Stultz wrote:
> > Just wanted to follow up on this as I've not seen the regression fix
> > land in 5.8-rc4 yet? Is it still pending, or did it fall through a
> > gap?
>
> No, it's in DaveM's -net tree currently, will go to Linus' tree on his next pull req:
>
> https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b338cb921e6739ff59ce32f43342779fe5ffa732

Great! Much appreciated! Sorry to nag!
-john