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e272602039
All existing users of NETLINK_URELEASE use it to clean up resources that were previously allocated to a socket via some command. As a result, no users require getting this notification for unbound sockets. Sending it for unbound sockets, however, is a problem because any user (including unprivileged users) can create a socket that uses the same ID as an existing socket. Binding this new socket will fail, but if the NETLINK_URELEASE notification is generated for such sockets, the users thereof will be tricked into thinking the socket that they allocated the resources for is closed. In the nl80211 case, this will cause destruction of virtual interfaces that still belong to an existing hostapd process; this is the case that Dmitry noticed. In the NFC case, it will cause a poll abort. In the case of netlink log/queue it will cause them to stop reporting events, as if NFULNL_CFG_CMD_UNBIND/NFQNL_CFG_CMD_UNBIND had been called. Fix this problem by checking that the socket is bound before generating the NETLINK_URELEASE notification. Cc: stable@vger.kernel.org Signed-off-by: Dmitry Ivanov <dima@ubnt.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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| .. | ||
| af_netlink.c | ||
| af_netlink.h | ||
| diag.c | ||
| genetlink.c | ||
| Kconfig | ||
| Makefile | ||