file->f_path.dentry is pinned down for as long as the file is open...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

kernel/auditsc.c

@@ -2405,7 +2405,6 @@ int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
 	struct audit_aux_data_bprm_fcaps *ax;
 	struct audit_context *context = current->audit_context;
 	struct cpu_vfs_cap_data vcaps;
-	struct dentry *dentry;
 
 	ax = kmalloc(sizeof(*ax), GFP_KERNEL);
 	if (!ax)
@@ -2415,9 +2414,7 @@ int __audit_log_bprm_fcaps(struct linux_binprm *bprm,
 	ax->d.next = context->aux;
 	context->aux = (void *)ax;
 
-	dentry = dget(bprm->file->f_path.dentry);
-	get_vfs_caps_from_disk(dentry, &vcaps);
-	dput(dentry);
+	get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
 
 	ax->fcap.permitted = vcaps.permitted;
 	ax->fcap.inheritable = vcaps.inheritable;

security/commoncap.c

@@ -434,7 +434,6 @@ int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data
  */
 static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_cap)
 {
-	struct dentry *dentry;
 	int rc = 0;
 	struct cpu_vfs_cap_data vcaps;
 
@@ -446,9 +445,7 @@ static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_c
 	if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
 		return 0;
 
-	dentry = dget(bprm->file->f_path.dentry);
-
-	rc = get_vfs_caps_from_disk(dentry, &vcaps);
+	rc = get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps);
 	if (rc < 0) {
 		if (rc == -EINVAL)
 			printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n",
@@ -464,7 +461,6 @@ static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_c
 		       __func__, rc, bprm->filename);
 
 out:
-	dput(dentry);
 	if (rc)
 		bprm_clear_caps(bprm);