From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 63F85413D69; Thu, 16 Jul 2026 14:14:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211297; cv=none; b=XTDoukSQD/rccrv79t4dgjDDqsBjyxdaNiEGwJHalzNPio1eLHlk3REoCbi/S8XjRpKVegxtkNM2DnGcDbhD79NGOVmrCN3qKgut7AMeVPH0HUPgbq0vBjM0zUznKf4bwuvuaDl1LcsPGb81CmWuKFCgdS6DJzyFgZOwbBu9hts= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784211297; c=relaxed/simple; bh=WVlYm33eScKNyLOHOCQJaPVeZObWfmWXbEGyh8g1NY8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pK0mGtpsf3b7y3xXuktb7NGteGmmQ6BxBhh9t1MoXs2s8FjazKGLKSH2VsR3cbMNDBTxL1SbWv+m0iex1p+4IkoylI2hPHEjrK++MWMgLfmGX+GX0K6DGSCL0LETOO+y24E3zHNCpbnFaTXFQRteZ+0lh/+xnpoqMzF8L9srdv4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vf/XqWqq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vf/XqWqq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8FAD1F000E9; Thu, 16 Jul 2026 14:14:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784211296; bh=6AcUiHjSlwUv9dIOwdyiKrm0/QvP2ILba3OvWnhznYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=vf/XqWqq+gfpnTe6CGnVZ7UPZ71+7BClnz03VsY2k5oIiBHG4yEz9KhyWIjqwoWTP 27JTX9vcOLYuXy2UrhokrOwoX9x4OSHf4XLUxBgqWFozR7UlU+I4hlzWxVZ8b/yHX6 G9Scr802yNloVeq6sa3pV2IqBh8O/TRWvT3Bw9OE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Bommarito , Jan Kara Subject: [PATCH 6.18 331/480] udf: validate free block extents against the partition length Date: Thu, 16 Jul 2026 15:31:18 +0200 Message-ID: <20260716133051.975311558@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260716133044.672218725@linuxfoundation.org> References: <20260716133044.672218725@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Bommarito commit 5f0419457f89dce1a3f1c8e62a3adf2f39ab8168 upstream. udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from that final bound. A crafted extent can pass the guard while logicalBlockNum + offset + count points past the partition, which later indexes past the space bitmap array. A single ftruncate(2) on a file backed by such an extent reliably panics the kernel. This is a local availability issue. On desktop systems where UDisks/polkit allows the active user to mount removable UDF media without CAP_SYS_ADMIN, an unprivileged local user can supply the crafted filesystem and trigger the panic by truncating a writable file on it. Systems that require root or CAP_SYS_ADMIN to mount the image have a higher prerequisite. No confidentiality or integrity impact is claimed: the reproduced primitive is an out-of-bounds read of a bitmap pointer slot followed by a kernel panic. Use the already computed logicalBlockNum + offset + count value for the partition length check. Also make load_block_bitmap() reject an out-of-range block group before indexing s_block_bitmap[], so corrupted callers cannot walk past the flexible array. Fixes: 56e69e59751d ("udf: prevent integer overflow in udf_bitmap_free_blocks()") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Link: https://patch.msgid.link/20260515142327.1120767-1-michael.bommarito@gmail.com Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/udf/balloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/fs/udf/balloc.c +++ b/fs/udf/balloc.c @@ -82,8 +82,9 @@ static int load_block_bitmap(struct supe int nr_groups = bitmap->s_nr_groups; if (block_group >= nr_groups) { - udf_debug("block_group (%u) > nr_groups (%d)\n", + udf_debug("block_group (%u) >= nr_groups (%d)\n", block_group, nr_groups); + return -EFSCORRUPTED; } if (bitmap->s_block_bitmap[block_group]) { @@ -662,7 +663,7 @@ void udf_free_blocks(struct super_block if (check_add_overflow(bloc->logicalBlockNum, offset, &blk) || check_add_overflow(blk, count, &blk) || - bloc->logicalBlockNum + count > map->s_partition_len) { + blk > map->s_partition_len) { udf_debug("Invalid request to free blocks: (%d, %u), off %u, " "len %u, partition len %u\n", partition, bloc->logicalBlockNum, offset, count,