From 13b4389143413a1f18127c07f72c74cad5b563e8 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 20 Jan 2016 11:26:01 -0500 Subject: [PATCH] SCSI: fix crashes in sd and sr runtime PM Runtime suspend during driver probe and removal can cause problems. The driver's runtime_suspend or runtime_resume callbacks may invoked before the driver has finished binding to the device or after the driver has unbound from the device. This problem shows up with the sd and sr drivers, and can cause disk or CD/DVD drives to become unusable as a result. The fix is simple. The drivers store a pointer to the scsi_disk or scsi_cd structure as their private device data when probing is finished, so we simply have to be sure to clear the private data during removal and test it during runtime suspend/resume. This fixes . Signed-off-by: Alan Stern Reported-by: Paul Menzel Reported-by: Erich Schubert Reported-by: Alexandre Rossi Tested-by: Paul Menzel Tested-by: Erich Schubert CC: Signed-off-by: James Bottomley --- drivers/scsi/sd.c | 7 +++++-- drivers/scsi/sr.c | 4 ++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 4e08d1cd704d..84fa4c46eaa6 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3268,8 +3268,8 @@ static int sd_suspend_common(struct device *dev, bool ignore_stop_errors) struct scsi_disk *sdkp = dev_get_drvdata(dev); int ret = 0; - if (!sdkp) - return 0; /* this can happen */ + if (!sdkp) /* E.g.: runtime suspend following sd_remove() */ + return 0; if (sdkp->WCE && sdkp->media_present) { sd_printk(KERN_NOTICE, sdkp, "Synchronizing SCSI cache\n"); @@ -3308,6 +3308,9 @@ static int sd_resume(struct device *dev) { struct scsi_disk *sdkp = dev_get_drvdata(dev); + if (!sdkp) /* E.g.: runtime resume at the start of sd_probe() */ + return 0; + if (!sdkp->device->manage_start_stop) return 0; diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 8bd54a64efd6..64c867405ad4 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -144,6 +144,9 @@ static int sr_runtime_suspend(struct device *dev) { struct scsi_cd *cd = dev_get_drvdata(dev); + if (!cd) /* E.g.: runtime suspend following sr_remove() */ + return 0; + if (cd->media_present) return -EBUSY; else @@ -985,6 +988,7 @@ static int sr_remove(struct device *dev) scsi_autopm_get_device(cd->device); del_gendisk(cd->disk); + dev_set_drvdata(dev, NULL); mutex_lock(&sr_ref_mutex); kref_put(&cd->kref, sr_kref_release);