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 95ABF22EED for ; Mon, 6 Nov 2023 13:27:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jm59DjY3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10510C433C8; Mon, 6 Nov 2023 13:27:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1699277269; bh=JZWWk2dGqjbr6v9bIUZ0HT4tJAbO00zIThuaUyedKDI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jm59DjY3tiRSa2Ac46cMQzt0akAGJi6iPM3wmYlb5CVK+AZkvtlGJvTlm3bDMheeD sJJove04Uug9swwAC35DLvNs537CANsv5u0hSLd0AlTV0T2pUkLc36dcarQwD6hzpc FpkB+XiByghtEo4ptKej4cR6u7mrO1Oca+TsbVNk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Baokun Li , "Ritesh Harjani (IBM)" , Theodore Tso Subject: [PATCH 5.15 066/128] ext4: avoid overlapping preallocations due to overflow Date: Mon, 6 Nov 2023 14:03:46 +0100 Message-ID: <20231106130312.100886875@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231106130309.112650042@linuxfoundation.org> References: <20231106130309.112650042@linuxfoundation.org> User-Agent: quilt/0.67 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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Baokun Li commit bedc5d34632c21b5adb8ca7143d4c1f794507e4c upstream. Let's say we want to allocate 2 blocks starting from 4294966386, after predicting the file size, start is aligned to 4294965248, len is changed to 2048, then end = start + size = 0x100000000. Since end is of type ext4_lblk_t, i.e. uint, end is truncated to 0. This causes (pa->pa_lstart >= end) to always hold when checking if the current extent to be allocated crosses already preallocated blocks, so the resulting ac_g_ex may cross already preallocated blocks. Hence we convert the end type to loff_t and use pa_logical_end() to avoid overflow. Signed-off-by: Baokun Li Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230724121059.11834-4-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Baokun Li Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4049,8 +4049,7 @@ ext4_mb_normalize_request(struct ext4_al struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); struct ext4_super_block *es = sbi->s_es; int bsbits, max; - ext4_lblk_t end; - loff_t size, start_off; + loff_t size, start_off, end; loff_t orig_size __maybe_unused; ext4_lblk_t start; struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); @@ -4158,7 +4157,7 @@ ext4_mb_normalize_request(struct ext4_al /* check we don't cross already preallocated blocks */ rcu_read_lock(); list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { - ext4_lblk_t pa_end; + loff_t pa_end; if (pa->pa_deleted) continue; @@ -4168,8 +4167,7 @@ ext4_mb_normalize_request(struct ext4_al continue; } - pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), - pa->pa_len); + pa_end = pa_logical_end(EXT4_SB(ac->ac_sb), pa); /* PA must not overlap original request */ BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end || @@ -4198,12 +4196,11 @@ ext4_mb_normalize_request(struct ext4_al /* XXX: extra loop to check we really don't overlap preallocations */ rcu_read_lock(); list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { - ext4_lblk_t pa_end; + loff_t pa_end; spin_lock(&pa->pa_lock); if (pa->pa_deleted == 0) { - pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), - pa->pa_len); + pa_end = pa_logical_end(EXT4_SB(ac->ac_sb), pa); BUG_ON(!(start >= pa_end || end <= pa->pa_lstart)); } spin_unlock(&pa->pa_lock);