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 A0D023F86F7; Fri, 15 May 2026 16:07:32 +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=1778861252; cv=none; b=LuCuqEoFF4rEXUm88jdkqfRwzuFiWHMuzcHKpoxLeH6PCAOgtxzB+Fji/tAXAvZgZAz+81ScwWZcQ4z7ucwGrzLDPs7v7hAM2eb/fDuW+ndcf2RvEwZHVnwCMJweLc17i/4hsl+fZotCLdWVSE8Nc0MXop+TzEYN9nOJWeLkz0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778861252; c=relaxed/simple; bh=iuJraftoh/JYF06oKE8YHwBLL/rqIwXbvZshACdDrUI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QFbMjm/cTHfD2DZTTl8eMkTfautYbnbxCxFTn9VzNuwMPXb3nZmjiDzIaGyYAX1X9ROjuCsA+OZASXrd+gK6WkLv9ruG+R+YiBLui5QUdEeQUgYdvjvhC9pzAg+OHy96EYTvQhgVWHrxrEt9aKfFHq3EiY1q3orCmnNeLE9YBVw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eMSKxIQG; 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="eMSKxIQG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24F51C2BCB0; Fri, 15 May 2026 16:07:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778861252; bh=iuJraftoh/JYF06oKE8YHwBLL/rqIwXbvZshACdDrUI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eMSKxIQG1V9uyAQwVbDYrCAooD3zHkRndYnUp56wLfRA2rpS4L4ArO3lDT7/+qNT/ 64sRbm+yK6tyxu/nQ5EQz7+jHQCeJhpOerJcqYGlMJf7uQtMTLKO+Orq/osrntIdVB f8i2wpu8+VW1mtvnE0av+slEC/rl3969logO5yzo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Bommarito , Jan Kara Subject: [PATCH 6.6 258/474] isofs: validate block number from NFS file handle in isofs_export_iget Date: Fri, 15 May 2026 17:46:07 +0200 Message-ID: <20260515154720.581751059@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154715.053014143@linuxfoundation.org> References: <20260515154715.053014143@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-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))