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 A60404432 for ; Mon, 11 Sep 2023 14:09:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29B96C433C7; Mon, 11 Sep 2023 14:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694441388; bh=pIdgnJZyTa7QG724ahtVNHOnIcrTyOKz4xg8OTeATm8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tCX27ehb3+30rN/+SJGD1xzeMohcwPF3KbxiJZNTTzsw0tLl8vVfsFtwXO64p6Ii0 0KxJrfmiN2zmJOJ3WM3NJRt4l4dUGmv8vVLPGCPFLr0yOJbiaG8Bhq6vG3pV/xBhkD Gc3R7Wp+tIcpUd7ecpezHkUyL05IdJj2C7pildwQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kemeng Shi , "Ritesh Harjani (IBM)" , Theodore Tso , Sasha Levin Subject: [PATCH 6.5 395/739] ext4: avoid potential data overflow in next_linear_group Date: Mon, 11 Sep 2023 15:43:14 +0200 Message-ID: <20230911134702.218104744@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.921299741@linuxfoundation.org> References: <20230911134650.921299741@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 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kemeng Shi [ Upstream commit 60c672b7f2d1e5dd1774f2399b355c9314e709f8 ] ngroups is ext4_group_t (unsigned int) while next_linear_group treat it in int. If ngroups is bigger than max number described by int, it will be treat as a negative number. Then "return group + 1 >= ngroups ? 0 : group + 1;" may keep returning 0. Switch int to ext4_group_t in next_linear_group to fix the overflow. Fixes: 196e402adf2e ("ext4: improve cr 0 / cr 1 group scanning") Signed-off-by: Kemeng Shi Reviewed-by: Ritesh Harjani (IBM) Link: https://lore.kernel.org/r/20230801143204.2284343-3-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/mballoc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b00b7adf1461d..a197ef71b7b02 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1080,8 +1080,9 @@ static inline int should_optimize_scan(struct ext4_allocation_context *ac) * Return next linear group for allocation. If linear traversal should not be * performed, this function just returns the same group */ -static int -next_linear_group(struct ext4_allocation_context *ac, int group, int ngroups) +static ext4_group_t +next_linear_group(struct ext4_allocation_context *ac, ext4_group_t group, + ext4_group_t ngroups) { if (!should_optimize_scan(ac)) goto inc_and_return; -- 2.40.1