4.19-stable review patch. If anyone has any objections, please let me know.
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From: Alexandra Winter wintera@linux.ibm.com
[ Upstream commit 2fe8a236436fe40d8d26a1af8d150fc80f04ee1a ]
Symptom: In case of a bad cable connection (e.g. dirty optics) a fast sequence of network DOWN-UP-DOWN-UP could happen. UP triggers recovery of the qeth interface. In case of a second DOWN while recovery is still ongoing, it can happen that the IP@ of a Layer3 qeth interface is lost and will not be recovered by the second UP.
Problem: When registration of IP addresses with Layer 3 qeth devices fails, (e.g. because of bad address format) the respective IP address is deleted from its hash-table in the driver. If registration fails because of a ENETDOWN condition, the address should stay in the hashtable, so a subsequent recovery can restore it.
3caa4af834df ("qeth: keep ip-address after LAN_OFFLINE failure") fixes this for registration failures during normal operation, but not during recovery.
Solution: Keep L3-IP address in case of ENETDOWN in qeth_l3_recover_ip(). For consistency with qeth_l3_add_ip() we also keep it in case of EADDRINUSE, i.e. for some reason the card already/still has this address registered.
Fixes: 4a71df50047f ("qeth: new qeth device driver") Cc: stable@vger.kernel.org Signed-off-by: Alexandra Winter wintera@linux.ibm.com Link: https://lore.kernel.org/r/20240206085849.2902775-1-wintera@linux.ibm.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/s390/net/qeth_l3_main.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 52e0ae4dc7241..e9102359e3134 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -285,9 +285,10 @@ static void qeth_l3_clear_ip_htable(struct qeth_card *card, int recover) if (!recover) { hash_del(&addr->hnode); kfree(addr); - continue; + } else { + /* prepare for recovery */ + addr->disp_flag = QETH_DISP_ADDR_ADD; } - addr->disp_flag = QETH_DISP_ADDR_ADD; }
spin_unlock_bh(&card->ip_lock); @@ -325,11 +326,13 @@ static void qeth_l3_recover_ip(struct qeth_card *card) } else rc = qeth_l3_register_addr_entry(card, addr);
- if (!rc) { + if (!rc || rc == -EADDRINUSE || rc == -ENETDOWN) { + /* keep it in the records */ addr->disp_flag = QETH_DISP_ADDR_DO_NOTHING; if (addr->ref_counter < 1) qeth_l3_delete_ip(card, addr); } else { + /* bad address */ hash_del(&addr->hnode); kfree(addr); }