[SCSI] sd name space exhaustion causes system hang
Following a site power outage which re-enabled all the ports on my FC
switches, my system subsequently booted with far too many luns! I had
let it run hoping it would make multi-user. It didn't. :( It hung solid
after exhausting the last sd device, sdzzz, and attempting to create sdaaaa
and beyond. I was unable to get a dump.
Discovered using a 2.6.32.13 based system.
correct this by detecting when the last index is utilized and failing
the sd probe of the device. Patch applies to scsi-misc-2.6.
Signed-off-by: Michael Reed <mdr@sgi.com>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 0c4f89cf..50f1fe6 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2288,11 +2288,10 @@
index = sdkp->index;
dev = &sdp->sdev_gendev;
- if (index < SD_MAX_DISKS) {
- gd->major = sd_major((index & 0xf0) >> 4);
- gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
- gd->minors = SD_MINORS;
- }
+ gd->major = sd_major((index & 0xf0) >> 4);
+ gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
+ gd->minors = SD_MINORS;
+
gd->fops = &sd_fops;
gd->private_data = &sdkp->driver;
gd->queue = sdkp->device->request_queue;
@@ -2382,6 +2381,12 @@
if (error)
goto out_put;
+ if (index >= SD_MAX_DISKS) {
+ error = -ENODEV;
+ sdev_printk(KERN_WARNING, sdp, "SCSI disk (sd) name space exhausted.\n");
+ goto out_free_index;
+ }
+
error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
if (error)
goto out_free_index;
