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 8D4E0379EDA; Thu, 20 Aug 2026 15:15:00 +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=1787238901; cv=none; b=TDaTJY8Y9ebeP0XwOsvkvscQIOZ8bdEJaOQ00N2/ot/8yRXK+IDij5RNBIyMR1jg9/zq7K9BClxoEIvZ7i/jyvZIPQZF5gv9iS7eKINoiOv4Ql9WDJEhB+XFXbqOgrguj125VxDXaueUiSloVP0KOvoAbbxtAKDW3vcvXTgC2cc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787238901; c=relaxed/simple; bh=oNa9BzqUAKVjkbI8BYjrQ/ngW/S+/Hxi6IDSC/iYsqo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H9WZZpmmTeVFy8XwHV5FPfG7D20wYGd0mZSgAC2TiohqBfHdqK81PepObqnjHfa/avhgFhLFSX+5DcDhmANy4aA+bvw8D5xzk5lJ9SFbPblYCaC8xP/pWSiNLUc9HUoH+3vqu48URQmq1pgX0Szba31Je271xm/Ao1SkkR/zN78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KYgP/Hwq; 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="KYgP/Hwq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E64DB1F000E9; Thu, 20 Aug 2026 15:14:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787238900; bh=VcWndUDg+hquW4+2vnnTlQAwTxRhYejGmsOnNajifZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KYgP/HwqjgDKpbvY/lzbxzgsdaC9isWTx/8C3KfUzF3SvFeIzKsc3oPnT810AeZSr mqdmfdNf3bhIr2BuKhEGqpZ4TXdxbNjzutn3ozbVzv3dZq40MpxNgOhpdCoAJfr8P5 Sp/t2xTyLJEcfCD6ueqlB5RtA1SMi0FaNowrKDI0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nayna Jain , R Nageswara Sastry , George Wilson , Madhavan Srinivasan Subject: [PATCH 6.18 041/217] powerpc/pseries: lparcfg - fix kbuf[] underflow Date: Thu, 20 Aug 2026 16:53:29 +0200 Message-ID: <20260820145238.855265638@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145237.531699751@linuxfoundation.org> References: <20260820145237.531699751@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: George Wilson commit fb442a6673ff1046bf67754957d95880fdb394b5 upstream. In lparcfg_write(), a count of 0 results in kbuf[] being indexed at -1. Check for count == 0 in the existing check for count > sizeof(kbuf) and return -EINVAL if true. Fixes: 74422e2b1939 ("powerpc/pseries: Remove VLA from lparcfg_write()") Acked-by: Nayna Jain Tested-by: R Nageswara Sastry Cc: stable@vger.kernel.org # 4.20 Signed-off-by: George Wilson Signed-off-by: Madhavan Srinivasan Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/pseries/lparcfg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/powerpc/platforms/pseries/lparcfg.c +++ b/arch/powerpc/platforms/pseries/lparcfg.c @@ -686,7 +686,7 @@ static ssize_t lparcfg_write(struct file if (!firmware_has_feature(FW_FEATURE_SPLPAR)) return -EINVAL; - if (count > sizeof(kbuf)) + if (count == 0 || count > sizeof(kbuf)) return -EINVAL; if (copy_from_user(kbuf, buf, count))