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 7B31B35AADD; Tue, 26 Aug 2025 14:30:54 +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=1756218655; cv=none; b=DB2Vf0p0B+TDrjGbeGJN60DM/dMXr6JNr7130xnK3iRlGl7OjgKQtNksPz7rorw2u1668tRe+iIklzRdp6FAUqEzUeaNYF/Ne/SYEA5mwlHw6mc2HN68indEr5U1uLXTI9QgOUP/p9Ldo+tkuRmzCSJigE1jVNUPdeDsxahd8sI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756218655; c=relaxed/simple; bh=anTHzID9FuEVynkE+aZkJWRQNREpyCKWrdIgQD60gV0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FY61sKIkL1BmPVKJEXUAh+s36Zeqhs84z5UvCUAzt2M6QUKHu6PgX6+CnXa8eKof3q/n1z1h/P+ZpcgIBiM+TM1lu1A7tJgGvKEW2yUX4FiKy5W/XQ5h2hNb4QbxvUxm5PbARLDrhb2u+aJz4AtukHVewK35AFm69gUqzgq8XzI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BzUHcZys; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BzUHcZys" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C8CEBC4CEF1; Tue, 26 Aug 2025 14:30:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756218654; bh=anTHzID9FuEVynkE+aZkJWRQNREpyCKWrdIgQD60gV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BzUHcZysdpLyug5C9QYjUn3vFw2k0bleieY1XWOG0GRoLnelm6HbH+XZWO0Jgdl6T cZtiZp3do3xmP2numty4CsrNFbLYOx7drvCQiEkZnChUobAMNkGxWDcogd9U+2ebY7 YVbALMos16ANn5/zmWFicAkxJmOwi1+NWjAgNJpk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Octavian Purdila , Cong Wang , "David S. Miller" , Harshit Mogalapalli Subject: [PATCH 5.4 051/403] net_sched: sch_sfq: use a temporary work area for validating configuration Date: Tue, 26 Aug 2025 13:06:17 +0200 Message-ID: <20250826110907.269075859@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110905.607690791@linuxfoundation.org> References: <20250826110905.607690791@linuxfoundation.org> User-Agent: quilt/0.68 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 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Octavian Purdila [ Upstream commit 8c0cea59d40cf6dd13c2950437631dd614fbade6 ] Many configuration parameters have influence on others (e.g. divisor -> flows -> limit, depth -> limit) and so it is difficult to correctly do all of the validation before applying the configuration. And if a validation error is detected late it is difficult to roll back a partially applied configuration. To avoid these issues use a temporary work area to update and validate the configuration and only then apply the configuration to the internal state. Signed-off-by: Octavian Purdila Acked-by: Cong Wang Signed-off-by: David S. Miller Signed-off-by: Harshit Mogalapalli Signed-off-by: Greg Kroah-Hartman --- net/sched/sch_sfq.c | 56 ++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 44 insertions(+), 12 deletions(-) --- a/net/sched/sch_sfq.c +++ b/net/sched/sch_sfq.c @@ -631,6 +631,15 @@ static int sfq_change(struct Qdisc *sch, struct red_parms *p = NULL; struct sk_buff *to_free = NULL; struct sk_buff *tail = NULL; + unsigned int maxflows; + unsigned int quantum; + unsigned int divisor; + int perturb_period; + u8 headdrop; + u8 maxdepth; + int limit; + u8 flags; + if (opt->nla_len < nla_attr_size(sizeof(*ctl))) return -EINVAL; @@ -656,36 +665,59 @@ static int sfq_change(struct Qdisc *sch, NL_SET_ERR_MSG_MOD(extack, "invalid limit"); return -EINVAL; } + sch_tree_lock(sch); + + limit = q->limit; + divisor = q->divisor; + headdrop = q->headdrop; + maxdepth = q->maxdepth; + maxflows = q->maxflows; + perturb_period = q->perturb_period; + quantum = q->quantum; + flags = q->flags; + + /* update and validate configuration */ if (ctl->quantum) - q->quantum = ctl->quantum; - WRITE_ONCE(q->perturb_period, ctl->perturb_period * HZ); + quantum = ctl->quantum; + perturb_period = ctl->perturb_period * HZ; if (ctl->flows) - q->maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); + maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS); if (ctl->divisor) { - q->divisor = ctl->divisor; - q->maxflows = min_t(u32, q->maxflows, q->divisor); + divisor = ctl->divisor; + maxflows = min_t(u32, maxflows, divisor); } if (ctl_v1) { if (ctl_v1->depth) - q->maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH); + maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH); if (p) { - swap(q->red_parms, p); - red_set_parms(q->red_parms, + red_set_parms(p, ctl_v1->qth_min, ctl_v1->qth_max, ctl_v1->Wlog, ctl_v1->Plog, ctl_v1->Scell_log, NULL, ctl_v1->max_P); } - q->flags = ctl_v1->flags; - q->headdrop = ctl_v1->headdrop; + flags = ctl_v1->flags; + headdrop = ctl_v1->headdrop; } if (ctl->limit) { - q->limit = min_t(u32, ctl->limit, q->maxdepth * q->maxflows); - q->maxflows = min_t(u32, q->maxflows, q->limit); + limit = min_t(u32, ctl->limit, maxdepth * maxflows); + maxflows = min_t(u32, maxflows, limit); } + /* commit configuration */ + q->limit = limit; + q->divisor = divisor; + q->headdrop = headdrop; + q->maxdepth = maxdepth; + q->maxflows = maxflows; + WRITE_ONCE(q->perturb_period, perturb_period); + q->quantum = quantum; + q->flags = flags; + if (p) + swap(q->red_parms, p); + qlen = sch->q.qlen; while (sch->q.qlen > q->limit) { dropped += sfq_drop(sch, &to_free);