* Re: [PATCH v2 1/1] certs: Explain the rationale to call panic()
2022-03-22 11:13 ` [PATCH v2 1/1] certs: Explain the rationale to call panic() Mickaël Salaün
@ 2022-03-22 17:39 ` Tyler Hicks
2022-03-22 20:31 ` Jarkko Sakkinen
2022-03-30 12:53 ` David Howells
2 siblings, 0 replies; 5+ messages in thread
From: Tyler Hicks @ 2022-03-22 17:39 UTC (permalink / raw)
To: Mickaël Salaün
Cc: Jarkko Sakkinen, David Howells, David S . Miller, David Woodhouse,
Eric Snowberg, Paul Moore, keyrings, linux-crypto, linux-kernel,
Mickaël Salaün
On 2022-03-22 12:13:23, Mickaël Salaün wrote:
> From: Mickaël Salaün <mic@linux.microsoft.com>
>
> The blacklist_init() function calls panic() for memory allocation
> errors. This change documents the reason why we don't return -ENODEV.
>
> Suggested-by: Paul Moore <paul@paul-moore.com> [1]
> Requested-by: Jarkko Sakkinen <jarkko@kernel.org> [1]
> Link: https://lore.kernel.org/r/YjeW2r6Wv55Du0bJ@iki.fi [1]
> Reviewed-by: Paul Moore <paul@paul-moore.com>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
> Link: https://lore.kernel.org/r/20220322111323.542184-2-mic@digikod.net
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Tyler
> ---
>
> Changes since v1:
> * Fix commit subject spelling spotted by David Woodhouse.
> * Reword one sentence as suggested by Paul Moore.
> * Add Reviewed-by Paul Moore.
> * Add Reviewed-by Jarkko Sakkinen.
> ---
> certs/blacklist.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/certs/blacklist.c b/certs/blacklist.c
> index 486ce0dd8e9c..25094ea73600 100644
> --- a/certs/blacklist.c
> +++ b/certs/blacklist.c
> @@ -307,6 +307,15 @@ static int restrict_link_for_blacklist(struct key *dest_keyring,
>
> /*
> * Initialise the blacklist
> + *
> + * The blacklist_init() function is registered as an initcall via
> + * device_initcall(). As a result if the blacklist_init() function fails for
> + * any reason the kernel continues to execute. While cleanly returning -ENODEV
> + * could be acceptable for some non-critical kernel parts, if the blacklist
> + * keyring fails to load it defeats the certificate/key based deny list for
> + * signed modules. If a critical piece of security functionality that users
> + * expect to be present fails to initialize, panic()ing is likely the right
> + * thing to do.
> */
> static int __init blacklist_init(void)
> {
> --
> 2.35.1
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 1/1] certs: Explain the rationale to call panic()
2022-03-22 11:13 ` [PATCH v2 1/1] certs: Explain the rationale to call panic() Mickaël Salaün
2022-03-22 17:39 ` Tyler Hicks
@ 2022-03-22 20:31 ` Jarkko Sakkinen
2022-03-30 12:53 ` David Howells
2 siblings, 0 replies; 5+ messages in thread
From: Jarkko Sakkinen @ 2022-03-22 20:31 UTC (permalink / raw)
To: Mickaël Salaün
Cc: David Howells, David S . Miller, David Woodhouse, Eric Snowberg,
Paul Moore, Tyler Hicks, keyrings, linux-crypto, linux-kernel,
Mickaël Salaün
On Tue, Mar 22, 2022 at 12:13:23PM +0100, Mickaël Salaün wrote:
> From: Mickaël Salaün <mic@linux.microsoft.com>
>
> The blacklist_init() function calls panic() for memory allocation
> errors. This change documents the reason why we don't return -ENODEV.
>
> Suggested-by: Paul Moore <paul@paul-moore.com> [1]
> Requested-by: Jarkko Sakkinen <jarkko@kernel.org> [1]
> Link: https://lore.kernel.org/r/YjeW2r6Wv55Du0bJ@iki.fi [1]
> Reviewed-by: Paul Moore <paul@paul-moore.com>
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
> Link: https://lore.kernel.org/r/20220322111323.542184-2-mic@digikod.net
> ---
>
> Changes since v1:
> * Fix commit subject spelling spotted by David Woodhouse.
> * Reword one sentence as suggested by Paul Moore.
> * Add Reviewed-by Paul Moore.
> * Add Reviewed-by Jarkko Sakkinen.
> ---
> certs/blacklist.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/certs/blacklist.c b/certs/blacklist.c
> index 486ce0dd8e9c..25094ea73600 100644
> --- a/certs/blacklist.c
> +++ b/certs/blacklist.c
> @@ -307,6 +307,15 @@ static int restrict_link_for_blacklist(struct key *dest_keyring,
>
> /*
> * Initialise the blacklist
> + *
> + * The blacklist_init() function is registered as an initcall via
> + * device_initcall(). As a result if the blacklist_init() function fails for
> + * any reason the kernel continues to execute. While cleanly returning -ENODEV
> + * could be acceptable for some non-critical kernel parts, if the blacklist
> + * keyring fails to load it defeats the certificate/key based deny list for
> + * signed modules. If a critical piece of security functionality that users
> + * expect to be present fails to initialize, panic()ing is likely the right
> + * thing to do.
> */
> static int __init blacklist_init(void)
> {
> --
> 2.35.1
>
Thank you, I'll put this into my "queue" folder and apply as soon I have
bandwidth.
BR, Jarkko
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 1/1] certs: Explain the rationale to call panic()
2022-03-22 11:13 ` [PATCH v2 1/1] certs: Explain the rationale to call panic() Mickaël Salaün
2022-03-22 17:39 ` Tyler Hicks
2022-03-22 20:31 ` Jarkko Sakkinen
@ 2022-03-30 12:53 ` David Howells
2 siblings, 0 replies; 5+ messages in thread
From: David Howells @ 2022-03-30 12:53 UTC (permalink / raw)
To: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?=
Cc: dhowells, Jarkko Sakkinen, David S . Miller, David Woodhouse,
Eric Snowberg, Paul Moore, Tyler Hicks, keyrings, linux-crypto,
linux-kernel, =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?=
Mickaël Salaün <mic@digikod.net> wrote:
> The blacklist_init() function calls panic() for memory allocation
> errors. This change documents the reason why we don't return -ENODEV.
Why, though?
This is only called whilst the kernel is booting. If you hit ENOMEM, you
aren't likely to get much further with the boot process.
David
^ permalink raw reply [flat|nested] 5+ messages in thread