Re: [PATCH] nvmet: fix a memory leak in controller identify

[Nilay Shroff <nilay@linux.ibm.com>]

On 1/24/25 4:30 PM, Sagi Grimberg wrote:
> Simply free an allocated buffer once we copied its content
> to the request sgl.
> 
> kmemleak complaint:
> unreferenced object 0xffff8cd40c388000 (size 4096):
>   comm "kworker/2:2H", pid 14739, jiffies 4401313113
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace (crc 0):
>     [<ffffffff9e01087a>] kmemleak_alloc+0x4a/0x90
>     [<ffffffff9d30324a>] __kmalloc_cache_noprof+0x35a/0x420
>     [<ffffffffc180b0e2>] nvmet_execute_identify+0x912/0x9f0 [nvmet]
>     [<ffffffffc181a72c>] nvmet_tcp_try_recv_pdu+0x84c/0xc90 [nvmet_tcp]
>     [<ffffffffc181ac02>] nvmet_tcp_io_work+0x82/0x8b0 [nvmet_tcp]
>     [<ffffffff9cfa7158>] process_one_work+0x178/0x3e0
>     [<ffffffff9cfa8e9c>] worker_thread+0x2ec/0x420
>     [<ffffffff9cfb2140>] kthread+0xf0/0x120
>     [<ffffffff9cee36a4>] ret_from_fork+0x44/0x70
>     [<ffffffff9ce7fdda>] ret_from_fork_asm+0x1a/0x30
> 
> Fixes: 84909f7decbd ("nvmet: use kzalloc instead of ZERO_PAGE in
> nvme_execute_identify_ns_nvm()")
> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
> ---
>  drivers/nvme/target/admin-cmd.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index e670dc185a96..acc138bbf8f2 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -1068,6 +1068,7 @@ static void nvme_execute_identify_ns_nvm(struct nvmet_req *req)
>  		goto out;
>  	}
>  	status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
> +	kfree(id);
>  out:
>  	nvmet_req_complete(req, status);
>  }

Looks good to me.

Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>