To: Dmitry Vyukov <dvyukov@google.com>
Cc: dledford@redhat.com, sean.hefty@intel.com, hal.rosenstock@gmail.com,
        leon@kernel.org, linux-rdma@vger.kernel.org,
        linux-kernel@vger.kernel.org, syzkaller@googlegroups.com
Subject: Re: [PATCH] infiniband: remove WARN that is not kernel bug
From: Valdis.Kletnieks@vt.edu
In-Reply-To: <1479468277-50798-1-git-send-email-dvyukov@google.com>
References: <1479468277-50798-1-git-send-email-dvyukov@google.com>
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Date: Fri, 18 Nov 2016 21:22:42 -0500
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On Fri, 18 Nov 2016 12:24:37 +0100, Dmitry Vyukov said:
> WARNINGs mean kernel bugs.
> The one in ucma_write() points to user programming error
> or a malicious attempt. This is not a kernel bug, remove it.

> -	if (WARN_ON_ONCE(!ib_safe_file_access(filp)))
> +	if (!ib_safe_file_access(filp))
>  		return -EACCES;

In that case, wouldn't this be better?

	if (!ib_safe_file_access(filp)) {
		printk_once("Process %d (%s) tried to do something hinky", pid, comm);
		return _EACCESS;
	}

so the sysadmin becomes aware of the malicious attempt?

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