[PATCH] Emulex FC HBA driver: fix overflow of statically allocated array

[PATCH] Emulex FC HBA driver: fix overflow of statically allocated array

[Jesper Juhl]

Hi,

The Coverity checker noticed that we may overrun a statically allocated 
array in drivers/scsi/lpfc/lpfc_sli.c::lpfc_sli_hbqbuf_find().

The case is this; In 'struct lpfc_hba' we have 

	#define LPFC_MAX_HBQS  4
	...
	struct lpfc_hba {
		...
		struct hbq_s hbqs[LPFC_MAX_HBQS];
		...
	};

But then in lpfc_sli_hbqbuf_find() we have this code 

	hbqno = tag >> 16;
	if (hbqno > LPFC_MAX_HBQS)
		return NULL;

if 'hbqno' ends up as exactely 4, then we won't return, and then this

	list_for_each_entry(d_buf, &phba->hbqs[hbqno].hbq_buffer_list, list) {

will cause an overflow of the statically allocated array at index 4, 
since the valid indices are only 0-3. 

I propose this patch, that simply changes the 'hbqno > LPFC_MAX_HBQS' 
into 'hbqno >= LPFC_MAX_HBQS' as a possible fix.


Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
---

 drivers/scsi/lpfc/lpfc_sli.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index ce5ff2b..e5337ad 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -675,7 +675,7 @@ lpfc_sli_hbqbuf_find(struct lpfc_hba *phba, uint32_t tag)
 	uint32_t hbqno;
 
 	hbqno = tag >> 16;
-	if (hbqno > LPFC_MAX_HBQS)
+	if (hbqno >= LPFC_MAX_HBQS)
 		return NULL;
 
 	list_for_each_entry(d_buf, &phba->hbqs[hbqno].hbq_buffer_list, list) {

Re: [PATCH] Emulex FC HBA driver: fix overflow of statically allocated array

[James Smart]

ACK

-- james s

Jesper Juhl wrote:
> I propose this patch, that simply changes the 'hbqno > LPFC_MAX_HBQS' 
> into 'hbqno >= LPFC_MAX_HBQS' as a possible fix.
> 
> 
> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
> ---
> 
>  drivers/scsi/lpfc/lpfc_sli.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)