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 E62B5517BAA; Mon, 21 Sep 2026 22:01:42 +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=1790028106; cv=none; b=H9lmc0RfqAOaQwwkUzAqkZ6xcmH+jf9iT/SWIPhEi73j7nX0bk68BKZtunHJ3+YUULDjWIipy/sqHNpfpswVBurHEwtj79YiwYW3deYPKFWXrr0tPKjFri7Dbu9LilFD36bLbKpIshP5+HeYwsVgNexUyf9BTF1CsGFSPymG8CI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790028106; c=relaxed/simple; bh=g772JZu5Ugt62u3TwjLFm2h33jZ8NQVOl1wKG2ANzPk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hZ56vI+Kc8npNMkpbSUJuocOxrbs0NNQg+OkafKMCdibyPeTTmlYCREvJJj6oColtf03zch3USoqGlMtHbtZMKEqfkHTU3Nhz6+scva4GaXiJbxxhQPOXKVF5Xd2i4DQYKHMHzdMiAILrne4G4QmXeXHtqjcL2ADSw6spRe/rMc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OJ/HLKSu; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OJ/HLKSu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6287C1F000FF; Mon, 21 Sep 2026 22:01:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790028102; bh=JP1mJjwKrY1zm80E+e1Ejj6Y1oTsfyKHyqpS8mqGfzI=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=OJ/HLKSu0E20UTtT7OaCbUHb8xih6+CzoNIYw8Ta6Pt4ee6G2hFWetr97NQeJqXKg vnOk7e1Adn5T2Ax0Y50EULK19ATfYO5/qsN4dXBQTQJ09nhJBSZrGaX+1/iXUl9H+C 6XXwFp+SK3Wamjss4B70VsZLmmAEM812AvSWIvTs0xwZuCTHqnIXAXt+2b/aw8KgMd YOSIotScIEoSP0vMH9mo0Bm0On87t6SsI197vN1zM/lQGCbuKXuVIV47Kf7bnhwZkQ zvV5OkBy+0WMfLzNkeasoJMuKIz+IklkCw2AhetRQH6Re0gdlSLLIoV/wii/fikWKj 3KQkRX6LRqjpg== Message-ID: Date: Tue, 22 Sep 2026 00:01:38 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] hfs: validate drAlBlkSiz and fs_ablocks in hfs_mdb_get() To: Viacheslav Dubeyko , Hui Peng , glaubitz@physik.fu-berlin.de, frank.li@vivo.com, brauner@kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260919222605.3794529-1-benquike@gmail.com> <1164821496f54d2fe03af44283d48db707a5e391.camel@dubeyko.com> From: Krzysztof Kozlowski Content-Language: en-US Autocrypt: addr=krzk@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 8bit On 21/09/2026 23:33, Viacheslav Dubeyko wrote: > On Sat, 2026-09-19 at 22:26 +0000, Hui Peng wrote: >> In hfs_mdb_get() (fs/hfs/mdb.c), reject images with allocation block >> size (drAlBlkSiz) of 0 or not a multiple of HFS_SECTOR_SIZE (512), or >> with fs_ablocks == 0, preventing a divide-by-zero trap and out-of- >> bounds >> bitmap scans on crafted HFS images. >> >> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") >> Assisted-by: LLM >> Signed-off-by: Hui Peng >> --- >> diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c >> index 277de712f9d4..9e78c561a3f1 100644 >> --- a/fs/hfs/mdb.c >> +++ b/fs/hfs/mdb.c >> @@ -204,6 +204,11 @@ int hfs_mdb_get(struct super_block *sb) >>   /* These parameters are read from the MDB, and never written >> */ >>   HFS_SB(sb)->part_start = part_start; >>   HFS_SB(sb)->fs_ablocks = be16_to_cpu(mdb->drNmAlBlks); >> + if (!HFS_SB(sb)->fs_ablocks) { > > This check doesn't look like checking that it's "not a multiple of > HFS_SECTOR_SIZE (512)". Could you make your check more accurate? In case you were not aware of: this patch is result of huge AI semi-autonomous work, basically close to spam posting style. Whatever you review you might be actually talking to an slop-agent, thus wasting your time. Best regards, Krzysztof