From: Al Viro <viro@zeniv.linux.org.uk>
To: Daniel Yang <danielyangkang@gmail.com>
Cc: Namjae Jeon <linkinjeon@kernel.org>,
Sungjong Seo <sj1557.seo@samsung.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
syzbot+e1c69cadec0f1a078e3d@syzkaller.appspotmail.com
Subject: Re: [PATCH v2] fs/exfat: resolve memory leak from exfat_create_upcase_table()
Date: Mon, 16 Sep 2024 23:12:11 +0100 [thread overview]
Message-ID: <20240916221211.GC3107530@ZenIV> (raw)
In-Reply-To: <CAGiJo8SBf4zsY-ZrZQh_hxYZ7=xObfcgFxbTnWOtcz9DORGueA@mail.gmail.com>
On Mon, Sep 16, 2024 at 02:58:43PM -0700, Daniel Yang wrote:
> In exfat_create_upcase_table, ENOMEM and EINVAL result in a jump to
> exfat_load_default_upcase_table where memory is also allocated. Since
> ENOMEM doesn't allocate memory, freeing null addresses will result in a
> double free.
Freeing null address is a no-op. Explicitly guaranteed, for the
same reason why C standard guarantees that free(NULL) is a no-op.
So you don't need to check if allocation had been done.
prev parent reply other threads:[~2024-09-16 22:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-16 5:21 [PATCH v2] fs/exfat: resolve memory leak from exfat_create_upcase_table() Daniel Yang
2024-09-16 11:26 ` Namjae Jeon
[not found] ` <CAGiJo8SBf4zsY-ZrZQh_hxYZ7=xObfcgFxbTnWOtcz9DORGueA@mail.gmail.com>
2024-09-16 22:12 ` Al Viro [this message]
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