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 B1C9744AB9F; Tue, 21 Jul 2026 22:52:32 +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=1784674353; cv=none; b=qsJvUd3cSiVfShRe6sn4WPtaVbI72jbU/bB0oq5en2HXyhOj2r4qCVtifyEQa5PjSVzn8uK6jRCwDBKAQr+enaYu/YV3OTTDqqNohGY/5+q6383RmwYiQcKZnrvLvIN+B93zIl8xh4Jrrjvoc5PAWhF75vsQTNVOjWrjnvvBC64= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784674353; c=relaxed/simple; bh=Imbt8DrGmpn+3+zhyFk0/91/DOfECz9/9/32to6uNno=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SANESbwGS0c3nmoak++U9ssCV4fqSwnGP2VKjMs0DEr3GMUAR6ETWHFM+Bx+5p28I6HFz9wA5m6tHDKaD8LaNLT4amb/44L68S1+/E2s80h/946ygRuZvhNkkq+7U/lI5aJqXYKW1QysKkLjvWn1O39oi0569bmriDouguE2avw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aJVMuD0Z; 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="aJVMuD0Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 239B71F000E9; Tue, 21 Jul 2026 22:52:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784674352; bh=GlNNERVbluS/KLeoLY8qud+wjgZ94PqzBC0cV37P3PQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=aJVMuD0ZAfoWNab7qBD8uTTxTK9ZmvF9t09kCNsOxz4ZJaqO/KpwXN3FQF+pc7K// 9EEXvCvBLZbCmdxVnxnYALg1xFCYnZVMYApsTew+InbcInztNh5oHD3MKZDJKZPjGH pSvLuIYMhhQidMnG/WZQEG/E2aap1QkZzDPe2zIU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Benjamin Marzinski , Mikulas Patocka Subject: [PATCH 5.10 510/699] dm-log: fix a bitset_size overflow on 32bit machines Date: Tue, 21 Jul 2026 17:24:29 +0200 Message-ID: <20260721152407.199284023@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152355.667394603@linuxfoundation.org> References: <20260721152355.667394603@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Marzinski commit 9743132a41f4d9d0e54c5f2adcb821b04796bab1 upstream. Commit c20e36b7631d ("dm log: fix out-of-bounds write due to region_count overflow") made sure that region_count could fit in an unsigned int. But the bitmap memory isn't allocated based on region_count. It uses bitset_size (a size_t variable). The first step of calculating bitset_size is to set it to region_count, rounded up to a multiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG smaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit architecture, this will make bitset_size wrap around to 0 and fail, despite region_count being valid. Since bitset_size gets divided by 8, it can hold any valid region_count. It just needs a special case to handle the rollover. If it is 0, the value rolled over, and bitset size should be set to the number of bytes needed to hold 2^32 bits. Signed-off-by: Benjamin Marzinski Signed-off-by: Mikulas Patocka Fixes: c20e36b7631d ("dm log: fix out-of-bounds write due to region_count overflow") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-log.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/md/dm-log.c +++ b/drivers/md/dm-log.c @@ -421,6 +421,9 @@ static int create_log_context(struct dm_ */ bitset_size = dm_round_up(region_count, BITS_PER_LONG); bitset_size >>= BYTE_SHIFT; + /* Handle dm_round_up rollover on 32-bit systems */ + if (!bitset_size) + bitset_size = 1UL << (BITS_PER_LONG - BYTE_SHIFT); lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);