From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-176.mta1.migadu.com (out-176.mta1.migadu.com [95.215.58.176]) (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 B569925A345 for ; Mon, 14 Apr 2025 09:37:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744623465; cv=none; b=uL91H1liPWECRdvZvQKk3mRBkWr2RDAJO/MYU6u4cANkCemRJPMraDRLJLwvZEqNr4SB6dXg8FncY4pz7MdCM8NnL90J19GfrLRWdtoFcfuuhtWVAC4HphErXGMEHWp33k85knd4vwunojZCxyq9gFZiBrvgeEgVk/DQ11a51nM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744623465; c=relaxed/simple; bh=RfmKRKgsCSXvsFbpEfR7G5fGocEUnY6wL7YBYirtd9I=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hyKb69O2bpebtdQ0azrDeU70IgqKbQeKYPpUlHMSPl/J1q+lsXoPlO5YjLD/4e2Dbsv2BA4HC+yBKSYlGrkazkCX1QXIh6+tLC1dAjy0ksIjDihya3PCbWiv4jHXwCOheOKUikTvA5Peg+klXC/Emx5VGYXcDv6amZXqlgI5G8A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=U5wwHp87; arc=none smtp.client-ip=95.215.58.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="U5wwHp87" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1744623449; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dq648+S4Hz/D1ux1j2t4fcnqzswyqgLomIbtcNpKqs4=; b=U5wwHp87Ecx4muexWBZG4O/daJF6fMDsFzfC9DSSkjunEY4Q8ztQUwKuWtT8w7pioc0OQq tQLTRrQoBCwOiS7+kl+xscSWXHHL027H2V6PZBWGyz124wyZ4kHxI/mjZXvvuG5tczS3bw uPwZ2Uz/ug3fORviq3lLflAf1TooDoQ= Date: Mon, 14 Apr 2025 10:37:26 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v1] ptp: ocp: fix NULL deref in _signal_summary_show To: Sagi Maimon , jonathan.lemon@gmail.com, richardcochran@gmail.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org References: <20250414085412.117120-1-maimon.sagi@gmail.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Vadim Fedorenko In-Reply-To: <20250414085412.117120-1-maimon.sagi@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 14/04/2025 09:54, Sagi Maimon wrote: > Sysfs signal show operations can invoke _signal_summary_show before > signal_out array elements are initialized, causing a NULL pointer > dereference. Add NULL checks for signal_out elements to prevent kernel > crashes. > > Fixes: b325af3cfab9 ("ptp: ocp: Add signal generators and update sysfs nodes") > Signed-off-by: Sagi Maimon > --- > drivers/ptp/ptp_ocp.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c > index 7945c6be1f7c..4c7893539cec 100644 > --- a/drivers/ptp/ptp_ocp.c > +++ b/drivers/ptp/ptp_ocp.c > @@ -3963,6 +3963,9 @@ _signal_summary_show(struct seq_file *s, struct ptp_ocp *bp, int nr) > bool on; > u32 val; > > + if (!bp->signal_out[nr]) > + return; > + > on = signal->running; > sprintf(label, "GEN%d", nr + 1); > seq_printf(s, "%7s: %s, period:%llu duty:%d%% phase:%llu pol:%d", That's not correct, the dereference of bp->signal_out[nr] happens before the check. But I just wonder how can that even happen? I believe the proper fix is to move ptp_ocp_attr_group_add() closer to the end of ptp_ocp_adva_board_init() like it's done for other boards. -- pw-bot: cr