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>
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 5cbc69b..4af1682 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;
}