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 32E2B44210A; Tue, 21 Jul 2026 22:25:16 +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=1784672717; cv=none; b=A9m+gYTXGc7QY6yyajGbv7mtYrgXHjc80K12qpIHeirhiHXCi3mejAEuE4hfM7fmSvrk8b4PRn26DhozfnPwAs13nP8knYA1sHbcSxwQj9opiOPm1V5Jqd8lZSWoK58nrwbAOZenkUZoj35AlWeP9qFFL1eDRrLeT1tnoJzvSK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784672717; c=relaxed/simple; bh=S/SBAgQ4nUY5/ur/stNm5IK/IjAOkvorjq45bYlUZI8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KOyvxdAChSP2TZyhS6XCCbdT2cNKzm+UJKWnbbvB2Wj881PKOF72B50adJDdKMKhc1d5KlOLBvn0/32gcTn/36hYxO8E6UiN1Ly7NWyq/DKNKNKU6ebccpEXacjzPsYuEAIwa+IO4HIOslSax8TzlL26S/foRuxVOdKrHQYsGlA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SnanfEaZ; 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="SnanfEaZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 985021F000E9; Tue, 21 Jul 2026 22:25:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784672716; bh=KLugIhHq6063egupdUFMyPZFSh/QXY4f2aWzQQZKpdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SnanfEaZo1sdmbEBNTMkRk6BcydFO4ZUCwFvC0GQhrsLpK9FTf+bSpj+LGTlPebXg 9vfeIv5rAqnXRvaxpQxWhfZRnZ6c2YxZaIvxFsTkM53lVUm9GMYbpF0mhc5OmRxn35 IqlMVN5gAdbhPJM0UwiQfgyEQvvj8GZyynk/wdb8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Bradley Morgan , Thomas Gleixner Subject: [PATCH 5.15 677/843] cpu: hotplug: Bound hotplug states sysfs output Date: Tue, 21 Jul 2026 17:25:12 +0200 Message-ID: <20260721152421.287511465@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Bradley Morgan commit 86f436567f2516a0083b210bedc933544826a2c3 upstream. states_show() adds CPU hotplug state names into a single sysfs buffer using sprintf(). With enough registered states, this can write past the end of the PAGE_SIZE buffer. Use sysfs_emit_at() so output is bounded. Fixes: 98f8cdce1db5 ("cpu/hotplug: Add sysfs state interface") Signed-off-by: Bradley Morgan Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260619163719.12103-2-include@grrlz.net Signed-off-by: Greg Kroah-Hartman --- kernel/cpu.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -2436,21 +2436,17 @@ static const struct attribute_group cpuh NULL }; -static ssize_t states_show(struct device *dev, - struct device_attribute *attr, char *buf) +static ssize_t states_show(struct device *dev, struct device_attribute *attr, char *buf) { - ssize_t cur, res = 0; + ssize_t res = 0; int i; mutex_lock(&cpuhp_state_mutex); for (i = CPUHP_OFFLINE; i <= CPUHP_ONLINE; i++) { struct cpuhp_step *sp = cpuhp_get_step(i); - if (sp->name) { - cur = sprintf(buf, "%3d: %s\n", i, sp->name); - buf += cur; - res += cur; - } + if (sp->name) + res += sysfs_emit_at(buf, res, "%3d: %s\n", i, sp->name); } mutex_unlock(&cpuhp_state_mutex); return res;