[PATCH 1/4] nvmet: fix NULL pointer dereference in nvmet_execute_identify_nslist()

[Hannes Reinecke]

On 7/30/26 6:31 AM, Guixin Liu wrote:
> When a host issues an Identify command with CNS 07h (Active Namespace ID
> List for a specific I/O Command Set), nvmet_execute_identify_nslist() is
> called with match_css set. The command-set filter dereferences req->ns,
> but this handler never calls nvmet_req_find_ns(), so req->ns is always
> NULL (nvmet_req_init() resets it to NULL). As soon as an enabled
> namespace with an NSID greater than the requested value exists,
> req->ns->csi dereferences a NULL pointer and oopses.
> 
> Besides the crash, the comparison is logically wrong: to filter the list
> by command set it must test the command set of the namespace being
> iterated, not a single fixed value. Use the loop variable ns->csi.
> 
> Fixes: 61c9967cd634 ("nvmet: implement active command set ns list")
> Signed-off-by: Guixin Liu <kanie at linux.alibaba.com>
> ---
>   drivers/nvme/target/admin-cmd.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
> index 01b799e92ae6..ab6a0a98dd5d 100644
> --- a/drivers/nvme/target/admin-cmd.c
> +++ b/drivers/nvme/target/admin-cmd.c
> @@ -958,7 +958,7 @@ static void nvmet_execute_identify_nslist(struct nvmet_req *req, bool match_css)
>   	nvmet_for_each_enabled_ns(&ctrl->subsys->namespaces, idx, ns) {
>   		if (ns->nsid <= min_nsid)
>   			continue;
> -		if (match_css && req->ns->csi != req->cmd->identify.csi)
> +		if (match_css && ns->csi != req->cmd->identify.csi)
>   			continue;
>   		list[i++] = cpu_to_le32(ns->nsid);
>   		if (i == buf_size / sizeof(__le32))

Reviewed-by: Hannes Reinecke <hare at suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare at suse.de                                +49 911 74053 688
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