Re: [PATCH v4 11/11] liveupdate: fix return value on session allocation failure

[Mike Rapoport]

On Mon, Apr 13, 2026 at 06:51:27PM +0000, Pasha Tatashin wrote:
> When session allocation fails during deserialization, the global 'err'
> variable was not updated before returning. This caused subsequent calls
> to luo_session_deserialize() to incorrectly report success.
> 
> Ensure 'err' is set to the error code from PTR_ERR(session). This
> ensures that an error is correctly returned to userspace when it
> attempts to open /dev/liveupdate in the new kernel if deserialization
> failed.
> 
> Signed-off-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
> ---
>  kernel/liveupdate/luo_session.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/liveupdate/luo_session.c b/kernel/liveupdate/luo_session.c
> index a3327a28fc1f..92b1af791889 100644
> --- a/kernel/liveupdate/luo_session.c
> +++ b/kernel/liveupdate/luo_session.c
> @@ -547,7 +547,8 @@ int luo_session_deserialize(void)
>  			pr_warn("Failed to allocate session [%.*s] during deserialization %pe\n",
>  				(int)sizeof(sh->ser[i].name),
>  				sh->ser[i].name, session);
> -			return PTR_ERR(session);
> +			err = PTR_ERR(session);

it's really not obvious that err is global and it should be set before
returning.

I'd suggest replacing all return with goto that will return err;
This way it should be clearer that since err is returned it should be set.

> +			return err;
>  		}
>  
>  		err = luo_session_insert(sh, session);
> -- 
> 2.43.0
> 

-- 
Sincerely yours,
Mike.