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 A8FA8164151; Wed, 7 Feb 2024 21:26:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707341174; cv=none; b=oHmSPcKvsLh6kYCi8XATiQ3BlOAsFMfYPIuZD1Ukw3FwC+dXjiaJ/kgyhVBoH6LXCv27ieFMDx+Q4dsebMbu2MFOt5n58K1sV/nROy7tvolhwIULeenbK9H6KNSV0PsKhqIU5JtIizbw7KeVl63LtMqDJ3UsE9tT9aa0Cz2fNd8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707341174; c=relaxed/simple; bh=ORX43V3TFChGeVJVBXVNJK5e24agEHtEdt7guGraZi4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=EkJZSwFRvZrWbOB/ufYqeX3KDAeecvqTKR8JD/Ny1zOZv+aexMeFOkKeVAsrfNXG4D6e+EiFSL3ytHSqF0VPKY5Ks9PxmoOr8s1mlJ6mr1+gjLMtC1EgiTevgnGJyiTBLDYhIyYX3xYKHZR36UFo7JWuhIlLUnwYZ1BGtUIm/AI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=roxxCAPi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="roxxCAPi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F368C433F1; Wed, 7 Feb 2024 21:26:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707341174; bh=ORX43V3TFChGeVJVBXVNJK5e24agEHtEdt7guGraZi4=; h=From:To:Cc:Subject:Date:From; b=roxxCAPiXbnU7ipGqKjaONhBjuzZou4PSRxnWUR4XQCpMXNsfswof0zUxma7j6uJ6 sU221J3UOO6Zju0qaS9E8R2KbFWPS0f63vSJ10u05TD885UMbOxLULBGZ04YfFyR7p 1LKUBLBgUqScX1V4S1VhDPMXTfI0LjpOCBsKSyIcFLfBBmpW2eHtXjI1xPUFeXj5gQ OgnWbZ0xCQghGzFEME0OQG3inbOwutOglpUVTnAVEAyFK+73MIMqbGZYhpZjqBLLQn rVSRvt+7ncQYaUkWvA1ChZINJgjB80qLtzFCCKGldxZhFM9mph7WArSEbz+Rnxui9L Vd072YBfU8uhw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Baokun Li , Jan Kara , Theodore Ts'o , Sasha Levin , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 01/23] ext4: avoid dividing by 0 in mb_update_avg_fragment_size() when block bitmap corrupt Date: Wed, 7 Feb 2024 16:25:42 -0500 Message-ID: <20240207212611.3793-1-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.148 Content-Transfer-Encoding: 8bit From: Baokun Li [ Upstream commit 993bf0f4c393b3667830918f9247438a8f6fdb5b ] Determine if bb_fragments is 0 instead of determining bb_free to eliminate the risk of dividing by zero when the block bitmap is corrupted. Signed-off-by: Baokun Li Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20240104142040.2835097-6-libaokun1@huawei.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/mballoc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index e44c28ceb9cd..3df3c3894f7b 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -853,7 +853,7 @@ mb_update_avg_fragment_size(struct super_block *sb, struct ext4_group_info *grp) { struct ext4_sb_info *sbi = EXT4_SB(sb); - if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_free == 0) + if (!test_opt2(sb, MB_OPTIMIZE_SCAN) || grp->bb_fragments == 0) return; write_lock(&sbi->s_mb_rb_lock); -- 2.43.0