[PATCH] enclosure: fix oops while iterating enclosure_status array

[Jeff Mahoney]

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....@intel.com>
Signed-off-by: Jeff Mahoney <je...@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'))
--
Jeff Mahoney
--
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[James Bottomley]

Adding linux-scsi to the cc list.

Patch looks fine to me, though, thanks.

James

--

[James Bottomley]

*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:

--

[James Bottomley]

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 */