1 files changed, 44 insertions, 30 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 6c68ffd6b4bb..99f835753596 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -55,6 +55,7 @@
 #include <linux/security.h>
 #endif /* CONFIG_NFSD_V4 */
 #include <linux/jhash.h>
+#include <linux/ima.h>
 
 #include <asm/uaccess.h>
 
@@ -100,36 +101,35 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
 {
         struct svc_export *exp = *expp, *exp2 = NULL;
         struct dentry *dentry = *dpp;
-        struct vfsmount *mnt = mntget(exp->ex_path.mnt);
-        struct dentry *mounts = dget(dentry);
+        struct path path = {.mnt = mntget(exp->ex_path.mnt),
+                            .dentry = dget(dentry)};
         int err = 0;
 
-        while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts));
+        while (d_mountpoint(path.dentry) && follow_down(&path))
+                ;
 
-        exp2 = rqst_exp_get_by_name(rqstp, mnt, mounts);
+        exp2 = rqst_exp_get_by_name(rqstp, &path);
         if (IS_ERR(exp2)) {
                 if (PTR_ERR(exp2) != -ENOENT)
                         err = PTR_ERR(exp2);
-                dput(mounts);
-                mntput(mnt);
+                path_put(&path);
                 goto out;
         }
         if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
                 /* successfully crossed mount point */
                 /*
-                 * This is subtle: dentry is *not* under mnt at this point.
-                 * The only reason we are safe is that original mnt is pinned
-                 * down by exp, so we should dput before putting exp.
+                 * This is subtle: path.dentry is *not* on path.mnt
+                 * at this point.  The only reason we are safe is that
+                 * original mnt is pinned down by exp, so we should
+                 * put path *before* putting exp
                  */
-                dput(dentry);
-                *dpp = mounts;
-                exp_put(exp);
+                *dpp = path.dentry;
+                path.dentry = dentry;
                 *expp = exp2;
-        } else {
-                exp_put(exp2);
-                dput(mounts);
+                exp2 = exp;
         }
-        mntput(mnt);
+        path_put(&path);
+        exp_put(exp2);
 out:
         return err;
 }
@@ -168,28 +168,29 @@ nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
                         /* checking mountpoint crossing is very different when stepping up */
                         struct svc_export *exp2 = NULL;
                         struct dentry *dp;
-                        struct vfsmount *mnt = mntget(exp->ex_path.mnt);
-                        dentry = dget(dparent);
-                        while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry))
+                        struct path path = {.mnt = mntget(exp->ex_path.mnt),
+                                            .dentry = dget(dparent)};
+
+                        while (path.dentry == path.mnt->mnt_root &&
+                               follow_up(&path))
                                 ;
-                        dp = dget_parent(dentry);
-                        dput(dentry);
-                        dentry = dp;
+                        dp = dget_parent(path.dentry);
+                        dput(path.dentry);
+                        path.dentry = dp;
 
-                        exp2 = rqst_exp_parent(rqstp, mnt, dentry);
+                        exp2 = rqst_exp_parent(rqstp, &path);
                         if (PTR_ERR(exp2) == -ENOENT) {
-                                dput(dentry);
                                 dentry = dget(dparent);
                         } else if (IS_ERR(exp2)) {
                                 host_err = PTR_ERR(exp2);
-                                dput(dentry);
-                                mntput(mnt);
+                                path_put(&path);
                                 goto out_nfserr;
                         } else {
+                                dentry = dget(path.dentry);
                                 exp_put(exp);
                                 exp = exp2;
                         }
-                        mntput(mnt);
+                        path_put(&path);
                 }
         } else {
                 fh_lock(fhp);
@@ -735,6 +736,8 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
                             flags, cred);
         if (IS_ERR(*filp))
                 host_err = PTR_ERR(*filp);
+        else
+                ima_counts_get(*filp);
 out_nfserr:
         err = nfserrno(host_err);
 out:
@@ -1015,6 +1018,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
         host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset);
         set_fs(oldfs);
         if (host_err >= 0) {
+                *cnt = host_err;
                 nfsdstats.io_write += host_err;
                 fsnotify_modify(file->f_path.dentry);
         }
@@ -1060,10 +1064,9 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
         }
 
         dprintk("nfsd: write complete host_err=%d\n", host_err);
-        if (host_err >= 0) {
+        if (host_err >= 0)
                 err = 0;
-                *cnt = host_err;
-        } else
+        else
                 err = nfserrno(host_err);
 out:
         return err;
@@ -2024,6 +2027,7 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
                                         struct dentry *dentry, int acc)
 {
         struct inode    *inode = dentry->d_inode;
+        struct path     path;
         int             err;
 
         if (acc == NFSD_MAY_NOP)
@@ -2096,7 +2100,17 @@ nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
         if (err == -EACCES && S_ISREG(inode->i_mode) &&
             acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE))
                 err = inode_permission(inode, MAY_EXEC);
+        if (err)
+                goto nfsd_out;
 
+        /* Do integrity (permission) checking now, but defer incrementing
+         * IMA counts to the actual file open.
+         */
+        path.mnt = exp->ex_path.mnt;
+        path.dentry = dentry;
+        err = ima_path_check(&path, acc & (MAY_READ | MAY_WRITE | MAY_EXEC),
+                             IMA_COUNT_LEAVE);
+nfsd_out:
         return err? nfserrno(err) : 0;
 }