NFSv4.1: Fix uninitialised variable in devicenotify

[ Upstream commit b05bf5c63b326ce1da84ef42498d8e0e292e694c ]

When decode_devicenotify_args() exits with no entries, we need to
ensure that the struct cb_devicenotifyargs is initialised to
{ 0, NULL } in order to avoid problems in
nfs4_callback_devicenotify().

Reported-by: <rtm@csail.mit.edu>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/nfs/callback.h b/fs/nfs/callback.h
index 6a20331..ccd4f24 100644 (file)
--- a/fs/nfs/callback.h
+++ b/fs/nfs/callback.h
@@ -170,7 +170,7 @@ struct cb_devicenotifyitem {
 };
 
 struct cb_devicenotifyargs {
-       int                              ndevs;
+       uint32_t                         ndevs;
        struct cb_devicenotifyitem       *devs;
 };
 

diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c
index ed9d580..f2bc5b5 100644 (file)
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -358,7 +358,7 @@ __be32 nfs4_callback_devicenotify(void *argp, void *resp,
                                  struct cb_process_state *cps)
 {
        struct cb_devicenotifyargs *args = argp;
-       int i;
+       uint32_t i;
        __be32 res = 0;
        struct nfs_client *clp = cps->clp;
        struct nfs_server *server = NULL;

diff --git a/fs/nfs/callback_xdr.c b/fs/nfs/callback_xdr.c
index 4c48d85..ce3d1d5 100644 (file)
--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -258,11 +258,9 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
                                void *argp)
 {
        struct cb_devicenotifyargs *args = argp;
+       uint32_t tmp, n, i;
        __be32 *p;
        __be32 status = 0;
-       u32 tmp;
-       int n, i;
-       args->ndevs = 0;
 
        /* Num of device notifications */
        p = xdr_inline_decode(xdr, sizeof(uint32_t));
@@ -271,7 +269,7 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
                goto out;
        }
        n = ntohl(*p++);
-       if (n <= 0)
+       if (n == 0)
                goto out;
        if (n > ULONG_MAX / sizeof(*args->devs)) {
                status = htonl(NFS4ERR_BADXDR);
@@ -330,19 +328,21 @@ __be32 decode_devicenotify_args(struct svc_rqst *rqstp,
                        dev->cbd_immediate = 0;
                }
 
-               args->ndevs++;
-
                dprintk("%s: type %d layout 0x%x immediate %d\n",
                        __func__, dev->cbd_notify_type, dev->cbd_layout_type,
                        dev->cbd_immediate);
        }
+       args->ndevs = n;
+       dprintk("%s: ndevs %d\n", __func__, args->ndevs);
+       return 0;
+err:
+       kfree(args->devs);
 out:
+       args->devs = NULL;
+       args->ndevs = 0;
        dprintk("%s: status %d ndevs %d\n",
                __func__, ntohl(status), args->ndevs);
        return status;
-err:
-       kfree(args->devs);
-       goto out;
 }
 
 static __be32 decode_sessionid(struct xdr_stream *xdr,