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Date:   Thu, 23 May 2019 20:35:23 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Gen Zhang <blackgod016574@gmail.com>
Cc:     rppt@linux.ibm.com, david.engraf@sysgo.com, steven.price@arm.com,
        osandov@fb.com, luc.vanoostenryck@gmail.com, axboe@kernel.dk,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] initramfs: Fix a missing-chek bug in dir_add()
Message-Id: <20190523203523.8f638f378b54df0ef7a18f9d@linux-foundation.org>
In-Reply-To: <20190524033045.GA6628@zhanggen-UX430UQ>
References: <20190524033045.GA6628@zhanggen-UX430UQ>
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On Fri, 24 May 2019 11:30:45 +0800 Gen Zhang <blackgod016574@gmail.com> wrote:

> In dir_add() and do_name(), de->name and vcollected are allocated by
> kstrdup(). And de->name and vcollected are dereferenced in the following
> codes. However, memory allocation functions such as kstrdup() may fail. 
> Dereferencing this null pointer may cause the kernel go wrong. Thus we
> should check these two kstrdup() operations.
> Further, if kstrdup() returns NULL, we should free de in dir_add().

We generally assume that memory allocations within __init code cannot
fail.  If one does fail, something quite horrid has happened.  The
resulting oops will provide the same information as the proposed panic()
anyway.