diff options
| author | Julian Wiedmann <jwi@linux.vnet.ibm.com> | 2018-02-27 18:58:14 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-08 22:41:19 -0800 |
| commit | 56f662db7f5629ee0f5566ac229bc8a188339550 (patch) | |
| tree | 8870cb954562c2dc73c35c3e00ffc6b7a8af4965 | |
| parent | 027637104ddf90f87d463002f369599e0cef6c1d (diff) | |
s390/qeth: fix double-free on IP add/remove race
[ Upstream commit 14d066c3531a87f727968cacd85bd95c75f59843 ]
Registering an IPv4 address with the HW takes quite a while, so we
temporarily drop the ip_htable lock. Any concurrent add/remove of the
same IP adjusts the IP's use count, and (on remove) is then blocked by
addr->in_progress.
After the register call has completed, we check the use count for
concurrently attempted add/remove calls - and possibly straight-away
deregister the IP again. This happens via l3_delete_ip(), which
1) looks up the queried IP in the htable (getting a reference to the
*same* queried object),
2) deregisters the IP from the HW, and
3) frees the IP object.
The caller in l3_add_ip() then does a second free on the same object.
For this case, skip all the extra checks and lookups in l3_delete_ip()
and just deregister & free the IP object ourselves.
Fixes: 5f78e29ceebf ("qeth: optimize IP handling in rx_mode callback")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/s390/net/qeth_l3_main.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index a283dec014f3..91650e8adcc4 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -319,7 +319,8 @@ int qeth_l3_add_ip(struct qeth_card *card, struct qeth_ipaddr *tmp_addr) (rc == IPA_RC_LAN_OFFLINE)) { addr->disp_flag = QETH_DISP_ADDR_DO_NOTHING; if (addr->ref_counter < 1) { - qeth_l3_delete_ip(card, addr); + qeth_l3_deregister_addr_entry(card, addr); + hash_del(&addr->hnode); kfree(addr); } } else { |