From: Jesper Juhl <jesper.juhl@gmail.com>
Date: Thu, 9 Aug 2007 18:47:15 +0000 (+0200)
Subject: [SCSI] lpfc: fix potential overflow of hbqs array
X-Git-Tag: v2.6.24-rc1~1290^2~167
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=a0a74e45057cc3138c29173e7b0b3db8b30939ae

[SCSI] lpfc: fix potential overflow of hbqs array

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>
Acked-by: James Smart <James.Smart@Emulex.Com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
---

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index ce5ff2bccba6..e5337ad4121e 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) {