From: "Jürgen Groß" <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: Ian Jackson <ian.jackson@eu.citrix.com>, Wei Liu <wl@xen.org>
Subject: Re: [Xen-devel] [PATCH] tools/xenstore: fix a use after free problem in xenstored
Date: Thu, 2 Apr 2020 16:25:18 +0200 [thread overview]
Message-ID: <1599c563-483c-05e1-9dc7-2d2ddf10d9c7@suse.com> (raw)
In-Reply-To: <20200324101257.20781-1-jgross@suse.com>
Ping?
On 24.03.20 11:12, Juergen Gross wrote:
> Commit 562a1c0f7ef3fb ("tools/xenstore: dont unlink connection object
> twice") introduced a potential use after free problem in
> domain_cleanup(): after calling talloc_unlink() for domain->conn
> domain->conn is set to NULL. The problem is that domain is registered
> as talloc child of domain->conn, so it might be freed by the
> talloc_unlink() call.
>
> Fixes: 562a1c0f7ef3fb ("tools/xenstore: dont unlink connection object twice")
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> tools/xenstore/xenstored_domain.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
> index baddaba5df..5858185211 100644
> --- a/tools/xenstore/xenstored_domain.c
> +++ b/tools/xenstore/xenstored_domain.c
> @@ -214,6 +214,7 @@ static void domain_cleanup(void)
> {
> xc_dominfo_t dominfo;
> struct domain *domain;
> + struct connection *conn;
> int notify = 0;
>
> again:
> @@ -230,8 +231,10 @@ static void domain_cleanup(void)
> continue;
> }
> if (domain->conn) {
> - talloc_unlink(talloc_autofree_context(), domain->conn);
> + /* domain is a talloc child of domain->conn. */
> + conn = domain->conn;
> domain->conn = NULL;
> + talloc_unlink(talloc_autofree_context(), conn);
> notify = 0; /* destroy_domain() fires the watch */
> goto again;
> }
>
prev parent reply other threads:[~2020-04-02 14:25 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 10:12 [Xen-devel] [PATCH] tools/xenstore: fix a use after free problem in xenstored Juergen Gross
2020-04-02 14:25 ` Jürgen Groß [this message]
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