[PATCH] nfsd: fix error handling bug in nfsd_nl_pool_mode_get_doit

[PATCH] nfsd: fix error handling bug in nfsd_nl_pool_mode_get_doit

[Jeff Layton]

As Jakub pointed out, I meant to use a bitwise or after the call to
nla_put_string. Also move the sunrpc_get_pool_mode call up in the
function, which simplifies the error handling a bit.

Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
Technically, I think the logical or works just as well as a bitwise or
here, but this is cleaner and maybe slightly more efficient. Chuck,
it's probably best to squash this into 84a570328ee.
---
 fs/nfsd/nfsctl.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 187e9be77b78..e5d2cc74ef77 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -2214,6 +2214,9 @@ int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info)
 	void *hdr;
 	int err;
 
+	if (sunrpc_get_pool_mode(buf, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+		return -ERANGE;
+
 	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
 	if (!skb)
 		return -ENOMEM;
@@ -2223,11 +2226,7 @@ int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info)
 	if (!hdr)
 		goto err_free_msg;
 
-	err = -ERANGE;
-	if (sunrpc_get_pool_mode(buf, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
-		goto err_free_msg;
-
-	err = nla_put_string(skb, NFSD_A_POOL_MODE_MODE, buf) ||
+	err = nla_put_string(skb, NFSD_A_POOL_MODE_MODE, buf) |
 	      nla_put_u32(skb, NFSD_A_POOL_MODE_NPOOLS, nfsd_nrpools(net));
 	if (err)
 		goto err_free_msg;

---
base-commit: 84a570328eefd4df2e201deb5d43d152e0aca55a
change-id: 20240614-nfsd-next-d5f6bbdf027d

Best regards,
-- 
Jeff Layton <jlayton@kernel.org>

Re: [PATCH] nfsd: fix error handling bug in nfsd_nl_pool_mode_get_doit

[Chuck Lever]

On Fri, Jun 14, 2024 at 08:59:10AM -0400, Jeff Layton wrote:
> As Jakub pointed out, I meant to use a bitwise or after the call to
> nla_put_string. Also move the sunrpc_get_pool_mode call up in the
> function, which simplifies the error handling a bit.
> 
> Cc: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
> Technically, I think the logical or works just as well as a bitwise or
> here, but this is cleaner and maybe slightly more efficient. Chuck,
> it's probably best to squash this into 84a570328ee.

Done, and pushed to nfsd-next.


> ---
>  fs/nfsd/nfsctl.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index 187e9be77b78..e5d2cc74ef77 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -2214,6 +2214,9 @@ int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info)
>  	void *hdr;
>  	int err;
>  
> +	if (sunrpc_get_pool_mode(buf, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
> +		return -ERANGE;
> +
>  	skb = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
>  	if (!skb)
>  		return -ENOMEM;
> @@ -2223,11 +2226,7 @@ int nfsd_nl_pool_mode_get_doit(struct sk_buff *skb, struct genl_info *info)
>  	if (!hdr)
>  		goto err_free_msg;
>  
> -	err = -ERANGE;
> -	if (sunrpc_get_pool_mode(buf, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
> -		goto err_free_msg;
> -
> -	err = nla_put_string(skb, NFSD_A_POOL_MODE_MODE, buf) ||
> +	err = nla_put_string(skb, NFSD_A_POOL_MODE_MODE, buf) |
>  	      nla_put_u32(skb, NFSD_A_POOL_MODE_NPOOLS, nfsd_nrpools(net));
>  	if (err)
>  		goto err_free_msg;
> 
> ---
> base-commit: 84a570328eefd4df2e201deb5d43d152e0aca55a
> change-id: 20240614-nfsd-next-d5f6bbdf027d
> 
> Best regards,
> -- 
> Jeff Layton <jlayton@kernel.org>
> 

-- 
Chuck Lever