* Re: [PATCH] enclosure: fix oops while iterating enclosure_status array
2009-11-20 21:43 ` [PATCH] enclosure: fix oops while iterating enclosure_status array James Bottomley
@ 2009-11-26 15:50 ` James Bottomley
0 siblings, 0 replies; 2+ messages in thread
From: James Bottomley @ 2009-11-26 15:50 UTC (permalink / raw)
To: Jeff Mahoney; +Cc: Linux Kernel Mailing List, Linus Torvalds, linux-scsi
On Fri, 2009-11-20 at 16:43 -0500, James Bottomley wrote:
> *really* (promise) adding linux-scsi to the cc list this time.
>
> Patch looks fine to me, though, thanks.
>
> James
>
> On Thu, 2009-11-19 at 19:23 -0500, Jeff Mahoney wrote:
> > enclosure_status is expected to be a NULL terminated array of strings
> > but isn't actually NULL terminated. When writing an invalid value to
> > /sys/class/enclosure/.../.../status, it goes off the end of the array
> > and Oopses.
> >
> > This patch uses the array size instead.
> >
> > Reported-by: Artur Wojcik <artur.wojcik@intel.com>
> > Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> > ---
> > drivers/misc/enclosure.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > --- a/drivers/misc/enclosure.c
> > +++ b/drivers/misc/enclosure.c
> > @@ -412,8 +412,9 @@ static ssize_t set_component_status(stru
> > struct enclosure_component *ecomp = to_enclosure_component(cdev);
> > int i;
> >
> > - for (i = 0; enclosure_status[i]; i++) {
> > - if (strncmp(buf, enclosure_status[i],
> > + for (i = 0; i < ARRAY_SIZE(enclosure_status); i++) {
> > + if (enclosure_status[i] &&
> > + strncmp(buf, enclosure_status[i],
> > strlen(enclosure_status[i])) == 0 &&
> > (buf[strlen(enclosure_status[i])] == '\n' ||
> > buf[strlen(enclosure_status[i])] == '\0'))
Actually, it's not fine ... it's giving this error:
drivers/misc/enclosure.c: In function 'set_component_status':
drivers/misc/enclosure.c:453: warning: array subscript is above array bounds
It's another place where there's an assumption that the array is zero
terminated.
I think the actual best fix is simply to make the assumption true, like
the patch below.
James
---
diff --git a/drivers/misc/enclosure.c b/drivers/misc/enclosure.c
index e9eae4a..1eac626 100644
--- a/drivers/misc/enclosure.c
+++ b/drivers/misc/enclosure.c
@@ -391,6 +391,7 @@ static const char *const enclosure_status [] = {
[ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
[ENCLOSURE_STATUS_UNKNOWN] = "unknown",
[ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
+ [ENCLOSURE_STATUS_MAX] = NULL,
};
static const char *const enclosure_type [] = {
diff --git a/include/linux/enclosure.h b/include/linux/enclosure.h
index 90d1c21..9a33c5f 100644
--- a/include/linux/enclosure.h
+++ b/include/linux/enclosure.h
@@ -42,6 +42,8 @@ enum enclosure_status {
ENCLOSURE_STATUS_NOT_INSTALLED,
ENCLOSURE_STATUS_UNKNOWN,
ENCLOSURE_STATUS_UNAVAILABLE,
+ /* last element for counting purposes */
+ ENCLOSURE_STATUS_MAX
};
/* SFF-8485 activity light settings */
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