| From | Greg Kroah-Hartman <> | Subject | [ 037/100] proc connector: reject unprivileged listener bumps | Date | Tue, 12 Mar 2013 15:31:22 -0700 |
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3.8-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook <keescook@chromium.org>
commit e70ab977991964a5a7ad1182799451d067e62669 upstream.
While PROC_CN_MCAST_LISTEN/IGNORE is entirely advisory, it was possible for an unprivileged user to turn off notifications for all listeners by sending PROC_CN_MCAST_IGNORE. Instead, require the same privileges as required for a multicast bind.
Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Matt Helsley <matthltc@us.ibm.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Acked-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/connector/cn_proc.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/connector/cn_proc.c +++ b/drivers/connector/cn_proc.c @@ -313,6 +313,12 @@ static void cn_proc_mcast_ctl(struct cn_ (task_active_pid_ns(current) != &init_pid_ns)) return; + /* Can only change if privileged. */ + if (!capable(CAP_NET_ADMIN)) { + err = EPERM; + goto out; + } + mc_op = (enum proc_cn_mcast_op *)msg->data; switch (*mc_op) { case PROC_CN_MCAST_LISTEN: @@ -325,6 +331,8 @@ static void cn_proc_mcast_ctl(struct cn_ err = EINVAL; break; } + +out: cn_proc_ack(err, msg->seq, msg->ack); }
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