Commit f27bac2761cab5a2e212dea602d22457a9aa6943 which converted sd to use ida instead of idr incorrectly removed sd_index_lock around id allocation and free. idr/ida do have internal locks but they protect their free object lists not the allocation itself. The caller is responsible for that. This missing synchronization led to the same id being assigned to multiple devices leading to oops. Revive sd_index_lock. Reported and tracked down by Stuart Hayes of Dell. Signed-off-by: Tejun Heo <tj@xxxxxxxxxx> Cc: James Bottomley <jbottomley@xxxxxxxxxx> --- drivers/scsi/sd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index d57566b..55310db 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -107,6 +107,7 @@ static void scsi_disk_release(struct device *cdev); static void sd_print_sense_hdr(struct scsi_disk *, struct scsi_sense_hdr *); static void sd_print_result(struct scsi_disk *, int); +static DEFINE_SPINLOCK(sd_index_lock); static DEFINE_IDA(sd_index_ida); /* This semaphore is used to mediate the 0->1 reference get in the @@ -1914,7 +1915,9 @@ static int sd_probe(struct device *dev) if (!ida_pre_get(&sd_index_ida, GFP_KERNEL)) goto out_put; + spin_lock(&sd_index_lock); error = ida_get_new(&sd_index_ida, &index); + spin_unlock(&sd_index_lock); } while (error == -EAGAIN); if (error) @@ -1936,7 +1939,9 @@ static int sd_probe(struct device *dev) return 0; out_free_index: + spin_lock(&sd_index_lock); ida_remove(&sd_index_ida, index); + spin_unlock(&sd_index_lock); out_put: put_disk(gd); out_free: @@ -1986,7 +1991,9 @@ static void scsi_disk_release(struct device *dev) struct scsi_disk *sdkp = to_scsi_disk(dev); struct gendisk *disk = sdkp->disk; + spin_lock(&sd_index_lock); ida_remove(&sd_index_ida, sdkp->index); + spin_unlock(&sd_index_lock); disk->private_data = NULL; put_disk(disk); -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
