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authorJulian Wiedmann <jwi@linux.vnet.ibm.com>2018-02-27 18:58:14 +0100
committerDavid S. Miller <davem@davemloft.net>2018-02-28 11:13:12 -0500
commit14d066c3531a87f727968cacd85bd95c75f59843 (patch)
tree890b77aed6e064e297bcb2d773ad8532e1cf0746 /drivers/s390
parent98d823ab1fbdcb13abc25b420f9bb71bade42056 (diff)
downloadlinux-14d066c3531a87f727968cacd85bd95c75f59843.tar.bz2
s390/qeth: fix double-free on IP add/remove race
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>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/net/qeth_l3_main.c3
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 34481b51029e..77cdb4fc7721 100644
--- a/drivers/s390/net/qeth_l3_main.c
+++ b/drivers/s390/net/qeth_l3_main.c
@@ -237,7 +237,8 @@ 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 {