From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E5D0C377567; Tue, 12 May 2026 17:57:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778608642; cv=none; b=tqOh3Gy9dOsCetCvZhIFalIdzkLh+fjYjmKuyB7g9zUjC+a5dqU7DgFdD9uyxXNBtzSQI1vauyi8qXb8LpXl3w+Y4N7G3cltUA9OMz3ORyF0yW0ZV7WtWRWJAvPoZxnY36oJGPHrMU0TWYNv8duuQFuqMHS75iS1GWP9PKlLOWQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778608642; c=relaxed/simple; bh=3xdMN296sD/Vd/xOANQuQXBLy5xOhp6CSHBwPltMOSc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Jev0EnHLPDbNoyx5s0kpzkqFY/dGovl6ZQJ+uTV2zp7lJRNpgn75hw7nOk0/j53PA3yFt6EvLQpZFfO0RtuN0FJHpazXRZYDTgRiprAJD0cwnB/ZIYFNtRVljTNLwLC5VB62AZNif13K5mKjcsuiRKK+QU9VgwC0qjx/Pv+Udz0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=zetH97Lv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="zetH97Lv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C21DC2BCB0; Tue, 12 May 2026 17:57:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778608641; bh=3xdMN296sD/Vd/xOANQuQXBLy5xOhp6CSHBwPltMOSc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zetH97LvH6yLStHhD5PkbYMrJilLZywhd2PZoa1S9MCRaLW+iy8o83H/doTIEm8MB mQHTwfeTvPCLIo6nSctP7QVQdaiT+ezxBoDhyfeksVLzTP9vZdP0syDouDKY1+sDEA EwwOOHbuZIyWQCXFpbhlZduR85xQhWusFsc7l0tY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Bommarito , Jan Kara Subject: [PATCH 6.18 157/270] isofs: validate block number from NFS file handle in isofs_export_iget Date: Tue, 12 May 2026 19:39:18 +0200 Message-ID: <20260512173941.753524144@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260512173938.452574370@linuxfoundation.org> References: <20260512173938.452574370@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Bommarito commit 24376458138387fb251e782e624c7776e9826796 upstream. isofs_fh_to_dentry() and isofs_fh_to_parent() pass an attacker- controlled block number (ifid->block or ifid->parent_block) from the NFS file handle to isofs_export_iget(), which only rejects block == 0 before calling isofs_iget() and ultimately sb_bread(). A crafted file handle with fh_len sufficient to pass the check added by commit 0405d4b63d08 ("isofs: Prevent the use of too small fid") can still drive the server to read any in-range block on the backing device as if it were an iso_directory_record. That earlier fix was assigned CVE-2025-37780. sb_bread() on an out-of-range block returns NULL cleanly via the EIO path, so there is no memory-safety violation. For in-range reads of adjacent-partition data on the same block device, the unrelated bytes end up in iso_inode_info fields that reach the NFS client as dentry metadata. The deployment surface (isofs exported over NFS from loop-mounted images) is narrow and requires an authenticated NFS peer, but the malformed-file-handle class is reportable as hardening next to the existing CVE-2025-37780 fix. Reject block >= ISOFS_SB(sb)->s_nzones in isofs_export_iget() so the check covers both isofs_fh_to_dentry() and isofs_fh_to_parent() call sites with a single line. Fixes: 0405d4b63d08 ("isofs: Prevent the use of too small fid") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260419212155.2169382-3-michael.bommarito@gmail.com Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/isofs/export.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/isofs/export.c +++ b/fs/isofs/export.c @@ -24,7 +24,7 @@ isofs_export_iget(struct super_block *sb { struct inode *inode; - if (block == 0) + if (block == 0 || block >= ISOFS_SB(sb)->s_nzones) return ERR_PTR(-ESTALE); inode = isofs_iget(sb, block, offset); if (IS_ERR(inode))