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 A701E3D9540; Thu, 16 Jul 2026 23:26:37 +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=1784244398; cv=none; b=CPK+rRQfllyQRtgwLGdrzNtBoVBMbblJ4hvSsOtV713Fwde2a9mA59QVdq1No0HvcoSU+MJf7tew0dYcW+menoU1OoWipu3e8RCsy9QMbV3jTLemX/NoYv9GFNJoCk2qFlgaXOFf0w+K5JAgnu3LDUipwpCmIID0XH9sLdXVgdw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784244398; c=relaxed/simple; bh=7deOdonkM5ZLxkiyJi+soIDv9Ujfe3A3+bHMyCagGy8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ubbh/k+2VQAD6JdZ9Fne0DXN90ov5cPm/qGY0SVH83bahx09C/nkvt3dCVDra00OwuYjhk80nVLFgQv/GsTIolfLZ9UEcZMwiDdu3lCnAP+Q5KDT/01aQ5hpfv1iJgnColUjrK4SlthdUio8FRnhUVvmh3h8l0isBXgOtuOH7wc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JPdgmSsR; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JPdgmSsR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0911F1F000E9; Thu, 16 Jul 2026 23:26:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784244397; bh=HxAdPZOiAb1QKYFuvzbFaotbr1YtZWAdMAQmJwNDpqI=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=JPdgmSsRpCM/2snuOipJvhGhnlW0RS5KLnncAabHfZlUhKdKy08Hlgie5cOTDDtHj DvZrJscgje5P17O808mLZrwbpKvjU3msSB5nKoZ06FDMKjzvUzyoAlFWVawGDXPQLb cLfRlBtm3Z3OrtgDsVVpFcpai5jA8qKv0Fq1FVgeCtBWNA0xAUIdnyO3uVIbuaaHvc LA5cxQ3SMy+vSKcl51Xb69W7Rwj6vposAB/bCdIdRxX5g7hd0qtSoMk+3G0hgy+USH 79BRSUCjCGy7XTQi6p5mpzHKvbyiJ4sL0l0l3XAwCEm3OSCkF+ERgMm8HADLTfl1Hb S/yXLQh1B+4WA== Message-ID: <592b00fd-d529-4373-a733-d9f53d225540@kernel.org> Date: Thu, 16 Jul 2026 17:26:35 -0600 Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] cpupower/debug/i386: check mmap return value in main To: longlong yan , trenn@suse.com, jwyatt@redhat.com, jkacur@redhat.com Cc: skhan@linuxfoundation.org, sageofredondo@gmail.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan References: <20260629031113.556-1-yanlonglong@kylinos.cn> Content-Language: en-US From: Shuah In-Reply-To: <20260629031113.556-1-yanlonglong@kylinos.cn> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/28/26 21:11, longlong yan wrote: > The return value of mmap() is not checked. On failure mmap() returns > MAP_FAILED, not NULL. If mmap() fails, the subsequent for-loop > dereferences the invalid pointer (MAP_FAILED), causing a segfault. > > Add a check for MAP_FAILED after mmap(), consistent with the existing > error handling style for open() in the same function. > > Fixes: 7fe2f6399a84 ("cpupowerutils - cpufrequtils extended with quite some features") > Signed-off-by: longlong yan > --- > tools/power/cpupower/debug/i386/dump_psb.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/tools/power/cpupower/debug/i386/dump_psb.c b/tools/power/cpupower/debug/i386/dump_psb.c > index 6fb81b42ea61..9da519200433 100644 > --- a/tools/power/cpupower/debug/i386/dump_psb.c > +++ b/tools/power/cpupower/debug/i386/dump_psb.c > @@ -181,6 +181,11 @@ main(int argc, char *argv[]) > > mem = mmap(mem, 0x100000 - 0xc0000, PROT_READ, MAP_SHARED, fd, 0xc0000); > close(fd); > + > + if (mem == MAP_FAILED) { > + printf ("Couldn't mmap /dev/mem\n"); > + exit(1); > + } > > for (p = mem; p - mem < LEN; p+=16) { > if (memcmp(p, "AMDK7PNOW!", 10) == 0) { Thank you for the patch. Sorry for a late response. Please send v2 after fixing checkpatch errors and warnings. thanks, -- Shuah