[PATCH] nvme-fabrics: error out to unlock the mutex

[Max Gurtovoy]

On 02/06/2023 8:37, Chaitanya Kulkarni wrote:
> Currently, in the nvmf_host_add() function, if the nvmf_host_alloc()
> call failed to allocate memory for the host, the code would directly
> return -ENOMEM without unlocking the nvmf_hosts_mutex. This could
> lead to potential issues with mutex synchronization.
> 
> Fix that error handling mechanism by jumping to the out_unlock label
> when nvmf_host_alloc() fails. This ensures that the mutex is unlocked
> before returning the error code. The updated code enhances avoids
> possible deadlocks.
> 
> Reported-by: kernel test robot <lkp at intel.com>
> Reported-by: Julia Lawall <julia.lawall at inria.fr>
> Closes: https://lore.kernel.org/r/202306020909.MTUEBeIa-lkp@intel.com/
> Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
> ---
>   drivers/nvme/host/fabrics.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
> index b1fa27b60917..c4345d1d98aa 100644
> --- a/drivers/nvme/host/fabrics.c
> +++ b/drivers/nvme/host/fabrics.c
> @@ -92,8 +92,10 @@ static struct nvmf_host *nvmf_host_add(const char *hostnqn, uuid_t *id)
>   	}
>   
>   	host = nvmf_host_alloc(hostnqn, id);
> -	if (!host)
> -		return ERR_PTR(-ENOMEM);
> +	if (!host) {
> +		host = ERR_PTR(-ENOMEM);
> +		goto out_unlock;
> +	}
>   
>   	list_add_tail(&host->list, &nvmf_hosts);
>   out_unlock:

Looks good,
Reviewed-by: Max Gurtovoy <mgurtovoy at nvidia.com>