[PATCH] RDMA/srp: Fix error handling in srp_add_port

[PATCH] RDMA/srp: Fix error handling in srp_add_port

[Ma Ke]

The reference count of the device incremented in device_initialize() is
not decremented when device_add() fails. Add a put_device() call before
returning from the function to decrement reference count for cleanup.
Or it could cause memory leak.

As comment of device_add() says, if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: c8e4c2397655 ("RDMA/srp: Rework the srp_add_port() error path")
Signed-off-by: Ma Ke <make_ruc2021@163.com>
---
 drivers/infiniband/ulp/srp/ib_srp.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 2916e77f589b..7289ae0b83ac 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -3978,7 +3978,6 @@ static struct srp_host *srp_add_port(struct srp_device *device, u32 port)
 	return host;
 
 put_host:
-	device_del(&host->dev);
 	put_device(&host->dev);
 	return NULL;
 }
-- 
2.25.1

Re: [PATCH] RDMA/srp: Fix error handling in srp_add_port

[Greg KH]

On Tue, Dec 17, 2024 at 03:55:38PM +0800, Ma Ke wrote:
> The reference count of the device incremented in device_initialize() is
> not decremented when device_add() fails. Add a put_device() call before
> returning from the function to decrement reference count for cleanup.
> Or it could cause memory leak.

That is not what you did here.  Please be more careful when sending out
"bugfixes" like this.

thanks,

greg k-h

Re: [PATCH] RDMA/srp: Fix error handling in srp_add_port

[Leon Romanovsky]

On Tue, 17 Dec 2024 15:55:38 +0800, Ma Ke wrote:
> The reference count of the device incremented in device_initialize() is
> not decremented when device_add() fails. Add a put_device() call before
> returning from the function to decrement reference count for cleanup.
> Or it could cause memory leak.
> 
> As comment of device_add() says, if device_add() succeeds, you should
> call device_del() when you want to get rid of it. If device_add() has
> not succeeded, use only put_device() to drop the reference count.
> 
> [...]

Applied, thanks!

[1/1] RDMA/srp: Fix error handling in srp_add_port
      https://git.kernel.org/rdma/rdma/c/a3cbf68c696111

Best regards,
-- 
Leon Romanovsky <leon@kernel.org>

Re: [PATCH] RDMA/srp: Fix error handling in srp_add_port

[Leon Romanovsky]

On Tue, Dec 17, 2024 at 03:55:38PM +0800, Ma Ke wrote:
> The reference count of the device incremented in device_initialize() is
> not decremented when device_add() fails. Add a put_device() call before
> returning from the function to decrement reference count for cleanup.
> Or it could cause memory leak.
> 
> As comment of device_add() says, if device_add() succeeds, you should
> call device_del() when you want to get rid of it. If device_add() has
> not succeeded, use only put_device() to drop the reference count.
> 
> Found by code review.
> 
> Cc: stable@vger.kernel.org

I slightly rewrote commit message and dropped this stable@ tag.

Thanks

> Fixes: c8e4c2397655 ("RDMA/srp: Rework the srp_add_port() error path")
> Signed-off-by: Ma Ke <make_ruc2021@163.com>
> ---
>  drivers/infiniband/ulp/srp/ib_srp.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
> index 2916e77f589b..7289ae0b83ac 100644
> --- a/drivers/infiniband/ulp/srp/ib_srp.c
> +++ b/drivers/infiniband/ulp/srp/ib_srp.c
> @@ -3978,7 +3978,6 @@ static struct srp_host *srp_add_port(struct srp_device *device, u32 port)
>  	return host;
>  
>  put_host:
> -	device_del(&host->dev);
>  	put_device(&host->dev);
>  	return NULL;
>  }
> -- 
> 2.25.1
>