CIFS: Fix undefined behavior when mount fails (b2e5cd33) · Commits · 戴 / test

fs/cifs/cifsfs.c

+17 −27

Original line number	Diff line number	Diff line
		@@ -104,29 +104,23 @@ cifs_sb_deactive(struct super_block *sb)
		}

		static int
		cifs_read_super(struct super_block sb, struct cifs_sb_info cifs_sb,
		void data, struct smb_vol volume_info, const char *devname,
		int silent)
		cifs_read_super(struct super_block sb, struct smb_vol volume_info,
		const char *devname, int silent)
		{
		struct inode *inode;
		struct cifs_sb_info *cifs_sb;
		int rc = 0;

		/* BB should we make this contingent on mount parm? */
		sb->s_flags \|= MS_NODIRATIME \| MS_NOATIME;
		sb->s_fs_info = cifs_sb;
		cifs_sb = CIFS_SB(sb);

		spin_lock_init(&cifs_sb->tlink_tree_lock);
		cifs_sb->tlink_tree = RB_ROOT;

		rc = bdi_setup_and_register(&cifs_sb->bdi, "cifs", BDI_CAP_MAP_COPY);
		if (rc) {
		kfree(cifs_sb);
		if (rc)
		return rc;
		}
		cifs_sb->bdi.ra_pages = default_backing_dev_info.ra_pages;

		if (data)
		cifs_sb->mountdata = data;
		cifs_sb->bdi.ra_pages = default_backing_dev_info.ra_pages;

		rc = cifs_mount(sb, cifs_sb, volume_info, devname);

		@@ -179,15 +173,7 @@ out_no_root:
		cifs_umount(sb, cifs_sb);

		out_mount_failed:
		if (cifs_sb) {
		if (cifs_sb->mountdata) {
		kfree(cifs_sb->mountdata);
		cifs_sb->mountdata = NULL;
		}
		unload_nls(cifs_sb->local_nls);
		bdi_destroy(&cifs_sb->bdi);
		kfree(cifs_sb);
		}
		return rc;
		}

		@@ -553,7 +539,6 @@ cifs_do_mount(struct file_system_type *fs_type,
		struct cifs_sb_info *cifs_sb;
		struct smb_vol *volume_info;
		struct dentry *root;
		char *copied_data = NULL;

		cFYI(1, "Devname: %s flags: %d ", dev_name, flags);

		@@ -576,20 +561,23 @@ cifs_do_mount(struct file_system_type *fs_type,
		goto out;
		}

		sb->s_flags = flags;

		/*
		* Copy mount params for use in submounts. Better to do
		* the copy here and deal with the error before cleanup gets
		* complicated post-mount.
		*/
		copied_data = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
		if (copied_data == NULL) {
		cifs_sb->mountdata = kstrndup(data, PAGE_SIZE, GFP_KERNEL);
		if (cifs_sb->mountdata == NULL) {
		root = ERR_PTR(-ENOMEM);
		goto err_out;
		}

		rc = cifs_read_super(sb, cifs_sb, copied_data, volume_info, dev_name,
		sb->s_flags = flags;
		/* BB should we make this contingent on mount parm? */
		sb->s_flags \|= MS_NODIRATIME \| MS_NOATIME;
		sb->s_fs_info = cifs_sb;

		rc = cifs_read_super(sb, volume_info, dev_name,
		flags & MS_SILENT ? 1 : 0);
		if (rc) {
		root = ERR_PTR(rc);
		@@ -604,6 +592,8 @@ out:
		return root;

		err_out:
		kfree(cifs_sb->mountdata);
		unload_nls(cifs_sb->local_nls);
		kfree(cifs_sb);
		deactivate_locked_super(sb);
		cifs_cleanup_volume_info(&volume_info);

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