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 1C43635C68D; Tue, 21 Jul 2026 21:16:58 +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=1784668620; cv=none; b=KBEP1TEQNmm4GtEwnigwtCmyqsioTHMkABQ0HWZGkQreDsEKEpKN01g8UZ65TnK5q+9caSfD/178VGEV4/FLJXTX/nhczerCRGnW/mU3cgQySw5wPAPlrhip+hI8ovSCioO3CxZkwuw4EpthtOFOUTAjvMZKeBo/YHDwG5pz/KI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784668620; c=relaxed/simple; bh=cbs0NI+hk+gxf8naA7BzVfHQuuZSxMguwF5ZSO3AThE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uVfPhi6WW5YtEbby8JSC3z6ipilC+SA/jUWhAfDFieSAI5cpcx+ub3a8dy74zYRMRq789GCDoy2JfWs3rl3xRNEG9CjacV7G/EDXiSek2de6Ye4BURQorR2NGY2gTMygTEX36+gm4If8jPVZUJaMkamdfYjett6baGeC5AccetY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GdMLXunL; 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="GdMLXunL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81DE01F000E9; Tue, 21 Jul 2026 21:16:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784668618; bh=Ym74trkzykcdN1yTm+fnuPMeQOBkvpdC03z8YbkvdB4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GdMLXunLSBKOFT7oZL2qADedsyCOpCNtlmLH8YisBkJ4QefM5Px0A/cTKSkfM8API GkOPJrCFmfvOXFxk9BBlDgDmUTSogXqqwuYWeJyb6CBU4LxPI1lq0YPxAQjN7lnvHJ NUq8Ezx3H8wmc36CSV5jhY3Xu/yZO+1+qT0ByW8g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Bommarito , Jan Kara Subject: [PATCH 6.1 0200/1067] udf: validate free block extents against the partition length Date: Tue, 21 Jul 2026 17:13:21 +0200 Message-ID: <20260721152429.067233639@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152424.521567757@linuxfoundation.org> References: <20260721152424.521567757@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 6.1-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 @@ -86,8 +86,9 @@ static int __load_block_bitmap(struct su 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]) { @@ -671,7 +672,7 @@ 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,