From: Stephen M. Cameron <[email protected]>
cciss: Make cciss_seq_show handle holes in the h->drv[] array.
It is possible (and expected) for there to be holes in the h->drv[]
array, that is, some elements may be NULL pointers. cciss_seq_show
needs to be made aware of this possibility to avoid an Oops.
To reproduce the Oops which this fixes:
1) Create two "arrays" in the Array Configuratino Utility and
several logical drives on each array.
2) cat /proc/driver/cciss/cciss* in an infinite loop
3) delete some of the logical drives in the first "array."
Signed-off-by: Stephen M. Cameron <[email protected]>
---
drivers/block/cciss.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 873e594..9291614 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -337,6 +337,9 @@ static int cciss_seq_show(struct seq_file *seq, void *v)
if (*pos > h->highest_lun)
return 0;
+ if (drv == NULL) /* it's possible for h->drv[] to have holes. */
+ return 0;
+
if (drv->heads == 0)
return 0;
On Thu, Feb 04 2010, Stephen M. Cameron wrote:
> From: Stephen M. Cameron <[email protected]>
>
> cciss: Make cciss_seq_show handle holes in the h->drv[] array.
> It is possible (and expected) for there to be holes in the h->drv[]
> array, that is, some elements may be NULL pointers. cciss_seq_show
> needs to be made aware of this possibility to avoid an Oops.
>
> To reproduce the Oops which this fixes:
>
> 1) Create two "arrays" in the Array Configuratino Utility and
> several logical drives on each array.
> 2) cat /proc/driver/cciss/cciss* in an infinite loop
> 3) delete some of the logical drives in the first "array."
>
> Signed-off-by: Stephen M. Cameron <[email protected]>
Thanks Stephen, applied for 2.6.33. BTW, you want to put that stable cc
into the patch itself as well, then it'll get picked up automatically
when Linus merges it.
--
Jens Axboe