[PATCH 2/2] config: android-recommended: Disable BPF_UNPRIV_DEFAULT_OFF for netd

[PATCH 2/2] config: android-recommended: Disable BPF_UNPRIV_DEFAULT_OFF for netd

[Marijn Suijten]

From: Marijn Suijten <marijns95@gmail.com>

AOSP's `netd` process fails to start on Android S:

    E ClatdController: getClatEgress4MapFd() failure: Operation not permitted
    I netd    : Initializing ClatdController: 410us
    E netd    : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])
    E netd    : CRITICAL: sleeping 60 seconds, netd exiting with failure, crash loop likely!

And on Android R:

    I ClatdController: 4.9+ kernel and device shipped with P - clat ebpf might work.
    E ClatdController: getClatEgressMapFd() failure: Operation not permitted
    I netd    : Initializing ClatdController: 1409us
    E netd    : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])

These permission issues are caused by 08389d888287 ("bpf: Add kconfig
knob for disabling unpriv bpf by default") because AOSP does not provide
netd the `SYS_ADMIN` capability, and also has no userspace support for
the `BPF` capability yet.

Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: John Stultz <john.stultz@linaro.org>
[John suggested this in https://linaro.atlassian.net/browse/ACK-107?focusedCommentId=117382]
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
---
 kernel/configs/android-recommended.config | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/configs/android-recommended.config b/kernel/configs/android-recommended.config
index 22bd76e43aca..e400fbbc8aba 100644
--- a/kernel/configs/android-recommended.config
+++ b/kernel/configs/android-recommended.config
@@ -1,4 +1,5 @@
 #  KEEP ALPHABETICALLY SORTED
+# CONFIG_BPF_UNPRIV_DEFAULT_OFF is not set
 # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
 # CONFIG_INPUT_MOUSE is not set
 # CONFIG_LEGACY_PTYS is not set
-- 
2.35.1

Re: [PATCH 2/2] config: android-recommended: Disable BPF_UNPRIV_DEFAULT_OFF for netd

[Marijn Suijten]

On 2022-02-02 10:33:55, Marijn Suijten wrote:
> From: Marijn Suijten <marijns95@gmail.com>

Feel free to disregard this `From:` override, didn't catch it when
preparing the patches from a different machine.

- Marijn

> AOSP's `netd` process fails to start on Android S:
> 
>     E ClatdController: getClatEgress4MapFd() failure: Operation not permitted
>     I netd    : Initializing ClatdController: 410us
>     E netd    : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])
>     E netd    : CRITICAL: sleeping 60 seconds, netd exiting with failure, crash loop likely!
> 
> And on Android R:
> 
>     I ClatdController: 4.9+ kernel and device shipped with P - clat ebpf might work.
>     E ClatdController: getClatEgressMapFd() failure: Operation not permitted
>     I netd    : Initializing ClatdController: 1409us
>     E netd    : Failed to start trafficcontroller: (Status[code: 1, msg: "Pinned map not accessible or does not exist: (/sys/fs/bpf/map_netd_cookie_tag_map): Operation not permitted"])
> 
> These permission issues are caused by 08389d888287 ("bpf: Add kconfig
> knob for disabling unpriv bpf by default") because AOSP does not provide
> netd the `SYS_ADMIN` capability, and also has no userspace support for
> the `BPF` capability yet.
> 
> Cc: Amit Pundir <amit.pundir@linaro.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: John Stultz <john.stultz@linaro.org>
> [John suggested this in https://linaro.atlassian.net/browse/ACK-107?focusedCommentId=117382]
> Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
> ---
>  kernel/configs/android-recommended.config | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/kernel/configs/android-recommended.config b/kernel/configs/android-recommended.config
> index 22bd76e43aca..e400fbbc8aba 100644
> --- a/kernel/configs/android-recommended.config
> +++ b/kernel/configs/android-recommended.config
> @@ -1,4 +1,5 @@
>  #  KEEP ALPHABETICALLY SORTED
> +# CONFIG_BPF_UNPRIV_DEFAULT_OFF is not set
>  # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set
>  # CONFIG_INPUT_MOUSE is not set
>  # CONFIG_LEGACY_PTYS is not set
> -- 
> 2.35.1
> 

Re: [PATCH 2/2] config: android-recommended: Disable BPF_UNPRIV_DEFAULT_OFF for netd

[Greg Kroah-Hartman]

On Wed, Feb 02, 2022 at 10:38:58AM +0100, Marijn Suijten wrote:
> On 2022-02-02 10:33:55, Marijn Suijten wrote:
> > From: Marijn Suijten <marijns95@gmail.com>
> 
> Feel free to disregard this `From:` override, didn't catch it when
> preparing the patches from a different machine.

Please resend with the correct one, otherwise our tools will get this
wrong when we try to commit it.

thanks,

greg k-h