Re: [PATCH v2] KEYS: trusted: Avoid calling null function trusted_key_exit

From: Sumit Garg
Date: Thu Jan 27 2022 - 00:43:01 EST


On Thu, 27 Jan 2022 at 02:02, Dave Kleikamp <dave.kleikamp@xxxxxxxxxx> wrote:
>
> If one loads and unloads the trusted module, trusted_key_exit can be
> NULL. Call it through static_call_cond() to avoid a kernel trap.
>
> Fixes: 5d0682be3189 ("KEYS: trusted: Add generic trusted keys framework")
> Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
> Cc: Sumit Garg <sumit.garg@xxxxxxxxxx>
> Cc: James Bottomley <jejb@xxxxxxxxxxxxx>
> Cc: Jarkko Sakkinen <jarkko@xxxxxxxxxx>
> Cc: Mimi Zohar <zohar@xxxxxxxxxxxxx>
> Cc: David Howells <dhowells@xxxxxxxxxx>
> Cc: James Morris <jmorris@xxxxxxxxx>
> Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx>
> Cc: linux-integrity@xxxxxxxxxxxxxxx
> Cc: keyrings@xxxxxxxxxxxxxxx
> Cc: linux-security-module@xxxxxxxxxxxxxxx
> ---
> v2 changes:
> Header cleanup - removed empty line and cc:stable
> security/keys/trusted-keys/trusted_core.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>

Thanks for the fix.

Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>

-Sumit

> diff --git a/security/keys/trusted-keys/trusted_core.c b/security/keys/trusted-keys/trusted_core.c
> index d5c891d8d353..8c14e04e2112 100644
> --- a/security/keys/trusted-keys/trusted_core.c
> +++ b/security/keys/trusted-keys/trusted_core.c
> @@ -351,7 +351,7 @@ static int __init init_trusted(void)
>
> static void __exit cleanup_trusted(void)
> {
> - static_call(trusted_key_exit)();
> + static_call_cond(trusted_key_exit)();
> }
>
> late_initcall(init_trusted);
> --
> 2.35.0
>