Thanks, Arnd! I'll send it for 4.9
Anna
On 11/22/2016 03:50 PM, Arnd Bergmann wrote:
> A correct bugfix introduced a harmless warning that shows up with gcc-7:
>
> fs/nfs/callback.c: In function 'nfs_callback_up':
> fs/nfs/callback.c:214:14: error: array subscript is outside array bounds
> [-Werror=array-bounds]
>
> What happens here is that the 'minorversion == 0' check tells the
> compiler that we assume minorversion can be something other than 0,
> but when CONFIG_NFS_V4_1 is disabled that would be invalid and
> result in an out-of-bounds access.
>
> The added check for IS_ENABLED(CONFIG_NFS_V4_1) tells gcc that this
> really can't happen, which makes the code slightly smaller and also
> avoids the warning.
>
> The bugfix that introduced the warning is marked for stable backports,
> we want this one backported to the same releases.
>
> Fixes: 98b0f80c2396 ("NFSv4.x: Fix a refcount leak in nfs_callback_up_net")
> Cc: sta...@vger.kernel.org # v3.7+
> Signed-off-by: Arnd Bergmann <a...@arndb.de>
> ---
> fs/nfs/callback.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
> index 532d8e242d4d..484bebc20bca 100644
> --- a/fs/nfs/callback.c
> +++ b/fs/nfs/callback.c
> @@ -197,7 +197,7 @@ static int nfs_callback_up_net(int minorversion, struct
> svc_serv *serv,
> }
>
> ret = -EPROTONOSUPPORT;
> - if (minorversion == 0)
> + if (!IS_ENABLED(CONFIG_NFS_V4_1) || minorversion == 0)
> ret = nfs4_callback_up_net(serv, net);
> else if (xprt->ops->bc_up)
> ret = xprt->ops->bc_up(serv, net);
>
