NFS - fix potential NULL pointer dereference v2

There is possible NULL pointer dereference if kstr[n]dup failed.
So fix them for safety.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index c99ca1f992ce..2215bcd24bd2 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1297,6 +1297,8 @@ static int nfs_validate_mount_data(void *options,
                 args->namlen            = data->namlen;
                 args->bsize             = data->bsize;
                 args->auth_flavors[0]   = data->pseudoflavor;
+                if (!args->nfs_server.hostname)
+                        goto out_nomem;
 
                 /*
                  * The legacy version 6 binary mount data from userspace has a
@@ -1343,6 +1345,8 @@ static int nfs_validate_mount_data(void *options,
                 len = c - dev_name;
                 /* N.B. caller will free nfs_server.hostname in all cases */
                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
+                if (!args->nfs_server.hostname)
+                        goto out_nomem;
 
                 c++;
                 if (strlen(c) > NFS_MAXPATHLEN)
@@ -1386,6 +1390,10 @@ out_v3_not_compiled:
         return -EPROTONOSUPPORT;
 #endif /* !CONFIG_NFS_V3 */
 
+out_nomem:
+        dfprintk(MOUNT, "NFS: not enough memory to handle mount options\n");
+        return -ENOMEM;
+
 out_no_address:
         dfprintk(MOUNT, "NFS: mount program didn't pass remote address\n");
         return -EINVAL;
@@ -1892,12 +1900,16 @@ static int nfs4_validate_mount_data(void *options,
                         return -ENAMETOOLONG;
                 /* N.B. caller will free nfs_server.hostname in all cases */
                 args->nfs_server.hostname = kstrndup(dev_name, len, GFP_KERNEL);
+                if (!args->nfs_server.hostname)
+                        goto out_nomem;
 
                 c++;                    /* step over the ':' */
                 len = strlen(c);
                 if (len > NFS4_MAXPATHLEN)
                         return -ENAMETOOLONG;
                 args->nfs_server.export_path = kstrndup(c, len, GFP_KERNEL);
+                if (!args->nfs_server.export_path)
+                        goto out_nomem;
 
                 dprintk("NFS: MNTPATH: '%s'\n", args->nfs_server.export_path);
 
@@ -1919,6 +1931,10 @@ out_inval_auth:
                  data->auth_flavourlen);
         return -EINVAL;
 
+out_nomem:
+        dfprintk(MOUNT, "NFS4: not enough memory to handle mount options\n");
+        return -ENOMEM;
+
 out_no_address:
         dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
         return -EINVAL;