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authorBart Van Assche <bart.vanassche@wdc.com>2018-02-22 11:30:20 -0800
committerMartin K. Petersen <martin.petersen@oracle.com>2018-03-01 20:16:52 -0500
commit3be8828fc507cdafe7040a3dcf361a2bcd8e305b (patch)
tree2649155f701f97e4094d4943ca60750470f8d3a3 /drivers/scsi
parentfa83e65885b9147e2f2b89fdd4ecf7b4ff91571d (diff)
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scsi: core: Avoid that ATA error handling can trigger a kernel hang or oops
Avoid that the recently introduced call_rcu() call in the SCSI core triggers a double call_rcu() call. Reported-by: Natanael Copa <ncopa@alpinelinux.org> Reported-by: Damien Le Moal <damien.lemoal@wdc.com> References: https://bugzilla.kernel.org/show_bug.cgi?id=198861 Fixes: 3bd6f43f5cb3 ("scsi: core: Ensure that the SCSI error handler gets woken up") Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com> Tested-by: Damien Le Moal <damien.lemoal@wdc.com> Cc: Natanael Copa <ncopa@alpinelinux.org> Cc: Damien Le Moal <damien.lemoal@wdc.com> Cc: Alexandre Oliva <oliva@gnu.org> Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/hosts.c3
-rw-r--r--drivers/scsi/scsi_error.c5
-rw-r--r--drivers/scsi/scsi_lib.c2
3 files changed, 5 insertions, 5 deletions
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 57bf43e34863..dd9464920456 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -328,8 +328,6 @@ static void scsi_host_dev_release(struct device *dev)
if (shost->work_q)
destroy_workqueue(shost->work_q);
- destroy_rcu_head(&shost->rcu);
-
if (shost->shost_state == SHOST_CREATED) {
/*
* Free the shost_dev device name here if scsi_host_alloc()
@@ -404,7 +402,6 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
INIT_LIST_HEAD(&shost->starved_list);
init_waitqueue_head(&shost->host_wait);
mutex_init(&shost->scan_mutex);
- init_rcu_head(&shost->rcu);
index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL);
if (index < 0)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index d042915ce895..ca53a5f785ee 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -223,7 +223,8 @@ static void scsi_eh_reset(struct scsi_cmnd *scmd)
static void scsi_eh_inc_host_failed(struct rcu_head *head)
{
- struct Scsi_Host *shost = container_of(head, typeof(*shost), rcu);
+ struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu);
+ struct Scsi_Host *shost = scmd->device->host;
unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
@@ -259,7 +260,7 @@ void scsi_eh_scmd_add(struct scsi_cmnd *scmd)
* Ensure that all tasks observe the host state change before the
* host_failed change.
*/
- call_rcu(&shost->rcu, scsi_eh_inc_host_failed);
+ call_rcu(&scmd->rcu, scsi_eh_inc_host_failed);
}
/**
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 5cbc69b2b1ae..4af1682f5ff5 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -670,6 +670,7 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
if (!blk_rq_is_scsi(req)) {
WARN_ON_ONCE(!(cmd->flags & SCMD_INITIALIZED));
cmd->flags &= ~SCMD_INITIALIZED;
+ destroy_rcu_head(&cmd->rcu);
}
if (req->mq_ctx) {
@@ -1150,6 +1151,7 @@ static void scsi_initialize_rq(struct request *rq)
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
scsi_req_init(&cmd->req);
+ init_rcu_head(&cmd->rcu);
cmd->jiffies_at_alloc = jiffies;
cmd->retries = 0;
}