From fa89adba1941e4f3b213399b81732a5c12fd9131 Mon Sep 17 00:00:00 2001 From: Jens Remus Date: Thu, 3 May 2018 13:52:47 +0200 Subject: scsi: zfcp: fix infinite iteration on ERP ready list zfcp_erp_adapter_reopen() schedules blocking of all of the adapter's rports via zfcp_scsi_schedule_rports_block() and enqueues a reopen adapter ERP action via zfcp_erp_action_enqueue(). Both are separately processed asynchronously and concurrently. Blocking of rports is done in a kworker by zfcp_scsi_rport_work(). It calls zfcp_scsi_rport_block(), which then traces a DBF REC "scpdely" via zfcp_dbf_rec_trig(). zfcp_dbf_rec_trig() acquires the DBF REC spin lock and then iterates with list_for_each() over the adapter's ERP ready list without holding the ERP lock. This opens a race window in which the current list entry can be moved to another list, causing list_for_each() to iterate forever on the wrong list, as the erp_ready_head is never encountered as terminal condition. Meanwhile the ERP action can be processed in the ERP thread by zfcp_erp_thread(). It calls zfcp_erp_strategy(), which acquires the ERP lock and then calls zfcp_erp_action_to_running() to move the ERP action from the ready to the running list. zfcp_erp_action_to_running() can move the ERP action using list_move() just during the aforementioned race window. It then traces a REC RUN "erator1" via zfcp_dbf_rec_run(). zfcp_dbf_rec_run() tries to acquire the DBF REC spin lock. If this is held by the infinitely looping kworker, it effectively spins forever. Example Sequence Diagram: Process ERP Thread rport_work ------------------- ------------------- ------------------- zfcp_erp_adapter_reopen() zfcp_erp_adapter_block() zfcp_scsi_schedule_rports_block() lock ERP zfcp_scsi_rport_work() zfcp_erp_action_enqueue(ZFCP_ERP_ACTION_REOPEN_ADAPTER) list_add_tail() on ready !(rport_task==RPORT_ADD) wake_up() ERP thread zfcp_scsi_rport_block() zfcp_dbf_rec_trig() zfcp_erp_strategy() zfcp_dbf_rec_trig() unlock ERP lock DBF REC zfcp_erp_wait() lock ERP | zfcp_erp_action_to_running() | list_for_each() ready | list_move() current entry | ready to running | zfcp_dbf_rec_run() endless loop over running | zfcp_dbf_rec_run_lvl() | lock DBF REC spins forever Any adapter recovery can trigger this, such as setting the device offline or reboot. V4.9 commit 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport during rport gone") introduced additional tracing of (un)blocking of rports. It missed that the adapter->erp_lock must be held when calling zfcp_dbf_rec_trig(). This fix uses the approach formerly introduced by commit aa0fec62391c ("[SCSI] zfcp: Fix sparse warning by providing new entry in dbf") that got later removed by commit ae0904f60fab ("[SCSI] zfcp: Redesign of the debug tracing for recovery actions."). Introduce zfcp_dbf_rec_trig_lock(), a wrapper for zfcp_dbf_rec_trig() that acquires and releases the adapter->erp_lock for read. Reported-by: Sebastian Ott Signed-off-by: Jens Remus Fixes: 4eeaa4f3f1d6 ("zfcp: close window with unblocked rport during rport gone") Cc: # 2.6.32+ Reviewed-by: Benjamin Block Signed-off-by: Steffen Maier Signed-off-by: Martin K. Petersen --- drivers/s390/scsi/zfcp_dbf.c | 23 ++++++++++++++++++++++- drivers/s390/scsi/zfcp_ext.h | 5 ++++- drivers/s390/scsi/zfcp_scsi.c | 14 +++++++------- 3 files changed, 33 insertions(+), 9 deletions(-) diff --git a/drivers/s390/scsi/zfcp_dbf.c b/drivers/s390/scsi/zfcp_dbf.c index a8b831000b2d..18c4f933e8b9 100644 --- a/drivers/s390/scsi/zfcp_dbf.c +++ b/drivers/s390/scsi/zfcp_dbf.c @@ -4,7 +4,7 @@ * * Debug traces for zfcp. * - * Copyright IBM Corp. 2002, 2017 + * Copyright IBM Corp. 2002, 2018 */ #define KMSG_COMPONENT "zfcp" @@ -308,6 +308,27 @@ void zfcp_dbf_rec_trig(char *tag, struct zfcp_adapter *adapter, spin_unlock_irqrestore(&dbf->rec_lock, flags); } +/** + * zfcp_dbf_rec_trig_lock - trace event related to triggered recovery with lock + * @tag: identifier for event + * @adapter: adapter on which the erp_action should run + * @port: remote port involved in the erp_action + * @sdev: scsi device involved in the erp_action + * @want: wanted erp_action + * @need: required erp_action + * + * The adapter->erp_lock must not be held. + */ +void zfcp_dbf_rec_trig_lock(char *tag, struct zfcp_adapter *adapter, + struct zfcp_port *port, struct scsi_device *sdev, + u8 want, u8 need) +{ + unsigned long flags; + + read_lock_irqsave(&adapter->erp_lock, flags); + zfcp_dbf_rec_trig(tag, adapter, port, sdev, want, need); + read_unlock_irqrestore(&adapter->erp_lock, flags); +} /** * zfcp_dbf_rec_run_lvl - trace event related to running recovery diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h index bf8ea4df2bb8..e5eed8aac0ce 100644 --- a/drivers/s390/scsi/zfcp_ext.h +++ b/drivers/s390/scsi/zfcp_ext.h @@ -4,7 +4,7 @@ * * External function declarations. * - * Copyright IBM Corp. 2002, 2016 + * Copyright IBM Corp. 2002, 2018 */ #ifndef ZFCP_EXT_H @@ -35,6 +35,9 @@ extern int zfcp_dbf_adapter_register(struct zfcp_adapter *); extern void zfcp_dbf_adapter_unregister(struct zfcp_adapter *); extern void zfcp_dbf_rec_trig(char *, struct zfcp_adapter *, struct zfcp_port *, struct scsi_device *, u8, u8); +extern void zfcp_dbf_rec_trig_lock(char *tag, struct zfcp_adapter *adapter, + struct zfcp_port *port, + struct scsi_device *sdev, u8 want, u8 need); extern void zfcp_dbf_rec_run(char *, struct zfcp_erp_action *); extern void zfcp_dbf_rec_run_lvl(int level, char *tag, struct zfcp_erp_action *erp); diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c index 4d2ba5682493..22f9562f415c 100644 --- a/drivers/s390/scsi/zfcp_scsi.c +++ b/drivers/s390/scsi/zfcp_scsi.c @@ -4,7 +4,7 @@ * * Interface to Linux SCSI midlayer. * - * Copyright IBM Corp. 2002, 2017 + * Copyright IBM Corp. 2002, 2018 */ #define KMSG_COMPONENT "zfcp" @@ -618,9 +618,9 @@ static void zfcp_scsi_rport_register(struct zfcp_port *port) ids.port_id = port->d_id; ids.roles = FC_RPORT_ROLE_FCP_TARGET; - zfcp_dbf_rec_trig("scpaddy", port->adapter, port, NULL, - ZFCP_PSEUDO_ERP_ACTION_RPORT_ADD, - ZFCP_PSEUDO_ERP_ACTION_RPORT_ADD); + zfcp_dbf_rec_trig_lock("scpaddy", port->adapter, port, NULL, + ZFCP_PSEUDO_ERP_ACTION_RPORT_ADD, + ZFCP_PSEUDO_ERP_ACTION_RPORT_ADD); rport = fc_remote_port_add(port->adapter->scsi_host, 0, &ids); if (!rport) { dev_err(&port->adapter->ccw_device->dev, @@ -642,9 +642,9 @@ static void zfcp_scsi_rport_block(struct zfcp_port *port) struct fc_rport *rport = port->rport; if (rport) { - zfcp_dbf_rec_trig("scpdely", port->adapter, port, NULL, - ZFCP_PSEUDO_ERP_ACTION_RPORT_DEL, - ZFCP_PSEUDO_ERP_ACTION_RPORT_DEL); + zfcp_dbf_rec_trig_lock("scpdely", port->adapter, port, NULL, + ZFCP_PSEUDO_ERP_ACTION_RPORT_DEL, + ZFCP_PSEUDO_ERP_ACTION_RPORT_DEL); fc_remote_port_delete(rport); port->rport = NULL; } -- cgit v1.2.3 From 125966db1fea12575ee21b2b3fc95a59032406f0 Mon Sep 17 00:00:00 2001 From: Prasanna Kumar Kalever Date: Thu, 10 May 2018 19:12:18 +0530 Subject: scsi: target: tcmu: fix error resetting qfull_time_out to default Problem: $ cat /sys/kernel/config/target/core/user_0/block/attrib/qfull_time_out -1 $ echo "-1" > /sys/kernel/config/target/core/user_0/block/attrib/qfull_time_out -bash: echo: write error: Invalid argument Fix: This patch will help reset qfull_time_out to its default i.e. qfull_time_out=-1. Signed-off-by: Prasanna Kumar Kalever Acked-by: Mike Christie Signed-off-by: Martin K. Petersen --- drivers/target/target_core_user.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 4ad89ea71a70..4f26bdc3d1dc 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -2121,6 +2121,8 @@ static ssize_t tcmu_qfull_time_out_store(struct config_item *item, if (val >= 0) { udev->qfull_time_out = val * MSEC_PER_SEC; + } else if (val == -1) { + udev->qfull_time_out = val; } else { printk(KERN_ERR "Invalid qfull timeout value %d\n", val); return -EINVAL; -- cgit v1.2.3 From a406b0a0693eafc6f6b3a633d25749370bf40d8c Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 13 May 2018 17:10:52 -0700 Subject: scsi: core: clean up generated file scsi_devinfo_tbl.c "make clean" should remove the generated file "scsi_devinfo_tbl.c", so list it in the clean-files variable so that the file gets cleaned up. Fixes: 345e29608b4b ("scsi: scsi: Export blacklist flags to sysfs") Cc: Hannes Reinecke Signed-off-by: Randy Dunlap Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen --- drivers/scsi/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile index e29f9b8fd66d..56c940394729 100644 --- a/drivers/scsi/Makefile +++ b/drivers/scsi/Makefile @@ -182,7 +182,7 @@ zalon7xx-objs := zalon.o ncr53c8xx.o NCR_Q720_mod-objs := NCR_Q720.o ncr53c8xx.o # Files generated that shall be removed upon make clean -clean-files := 53c700_d.h 53c700_u.h +clean-files := 53c700_d.h 53c700_u.h scsi_devinfo_tbl.c $(obj)/53c700.o $(MODVERDIR)/$(obj)/53c700.ver: $(obj)/53c700_d.h -- cgit v1.2.3 From a45b599ad808c3c982fdcdc12b0b8611c2f92824 Mon Sep 17 00:00:00 2001 From: Alexander Potapenko Date: Fri, 18 May 2018 16:23:18 +0200 Subject: scsi: sg: allocate with __GFP_ZERO in sg_build_indirect() This shall help avoid copying uninitialized memory to the userspace when calling ioctl(fd, SG_IO) with an empty command. Reported-by: syzbot+7d26fc1eea198488deab@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Alexander Potapenko Acked-by: Douglas Gilbert Reviewed-by: Johannes Thumshirn Signed-off-by: Martin K. Petersen --- drivers/scsi/sg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index c198b96368dd..5c40d809830f 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1894,7 +1894,7 @@ retry: num = (rem_sz > scatter_elem_sz_prev) ? scatter_elem_sz_prev : rem_sz; - schp->pages[k] = alloc_pages(gfp_mask, order); + schp->pages[k] = alloc_pages(gfp_mask | __GFP_ZERO, order); if (!schp->pages[k]) goto out; -- cgit v1.2.3