From: Javed Hasan jhasan@marvell.com
[ Upstream commit 823a65409c8990f64c5693af98ce0e7819975cba ]
When an rport event (RPORT_EV_READY) is updated without work being queued, avoid taking an additional reference.
This issue was leading to memory leak. Trace from KMEMLEAK tool:
unreferenced object 0xffff8888259e8780 (size 512): comm "kworker/2:1", jiffies 4433237386 (age 113021.971s) hex dump (first 32 bytes): 58 0a ec cf 83 88 ff ff 00 00 00 00 00 00 00 00 01 00 00 00 08 00 00 00 13 7d f0 1e 0e 00 00 10 backtrace: [<000000006b25760f>] fc_rport_recv_req+0x3c6/0x18f0 [libfc] [<00000000f208d994>] fc_lport_recv_els_req+0x120/0x8a0 [libfc] [<00000000a9c437b8>] fc_lport_recv+0xb9/0x130 [libfc] [<00000000a9c437b8>] fc_lport_recv+0xb9/0x130 [libfc] [<00000000ad5be37b>] qedf_ll2_process_skb+0x73d/0xad0 [qedf] [<00000000e0eb6893>] process_one_work+0x382/0x6c0 [<000000002dfd9e21>] worker_thread+0x57/0x5c0 [<00000000b648204f>] kthread+0x1a0/0x1c0 [<0000000072f5ab20>] ret_from_fork+0x35/0x40 [<000000001d5c05d8>] 0xffffffffffffffff
Below is the log sequence which leads to memory leak. Here we get the RPORT_EV_READY and RPORT_EV_STOP back to back, which lead to overwrite the event RPORT_EV_READY by event RPORT_EV_STOP. Because of this, kref_count gets incremented by 1.
kernel: host0: rport fffce5: Received PLOGI request kernel: host0: rport fffce5: Received PLOGI in INIT state kernel: host0: rport fffce5: Port is Ready kernel: host0: rport fffce5: Received PRLI request while in state Ready kernel: host0: rport fffce5: PRLI rspp type 8 active 1 passive 0 kernel: host0: rport fffce5: Received LOGO request while in state Ready kernel: host0: rport fffce5: Delete port kernel: host0: rport fffce5: Received PLOGI request kernel: host0: rport fffce5: Received PLOGI in state Delete - send busy kernel: host0: rport fffce5: work event 3 kernel: host0: rport fffce5: lld callback ev 3 kernel: host0: rport fffce5: work delete
Link: https://lore.kernel.org/r/20200626094959.32151-1-jhasan@marvell.com Reviewed-by: Girish Basrur gbasrur@marvell.com Reviewed-by: Saurav Kashyap skashyap@marvell.com Reviewed-by: Shyam Sundar ssundar@marvell.com Signed-off-by: Javed Hasan jhasan@marvell.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/libfc/fc_rport.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/libfc/fc_rport.c b/drivers/scsi/libfc/fc_rport.c index f39d2d62b002f..2b3239765c249 100644 --- a/drivers/scsi/libfc/fc_rport.c +++ b/drivers/scsi/libfc/fc_rport.c @@ -495,10 +495,11 @@ static void fc_rport_enter_delete(struct fc_rport_priv *rdata,
fc_rport_state_enter(rdata, RPORT_ST_DELETE);
- kref_get(&rdata->kref); - if (rdata->event == RPORT_EV_NONE && - !queue_work(rport_event_queue, &rdata->event_work)) - kref_put(&rdata->kref, fc_rport_destroy); + if (rdata->event == RPORT_EV_NONE) { + kref_get(&rdata->kref); + if (!queue_work(rport_event_queue, &rdata->event_work)) + kref_put(&rdata->kref, fc_rport_destroy); + }
rdata->event = event; }