From a370e2d653e5ff66364d098a47a512a1eafd17a1 Mon Sep 17 00:00:00 2001
From: Alexandra Diupina <adiupina@astralinux.ru>
Date: Fri, 28 Jul 2023 15:35:21 +0300
Subject: [PATCH] scsi: 53c700: Check that command slot is not NULL
commit 8366d1f1249a0d0bba41d0bd1298d63e5d34c7f7 upstream.
Add a check for the command slot value to avoid dereferencing a NULL
pointer.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Co-developed-by: Vladimir Telezhnikov <vtelezhnikov@astralinux.ru>
Signed-off-by: Vladimir Telezhnikov <vtelezhnikov@astralinux.ru>
Signed-off-by: Alexandra Diupina <adiupina@astralinux.ru>
Link: https://lore.kernel.org/r/20230728123521.18293-1-adiupina@astralinux.ru
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/53c700.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index 3242ff63986fd..37e1994c1f814 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -1600,7 +1600,7 @@ NCR_700_intr(int irq, void *dev_id)
printk("scsi%d (%d:%d) PHASE MISMATCH IN SEND MESSAGE %d remain, return %p[%04x], phase %s\n", host->host_no, pun, lun, count, (void *)temp, temp - hostdata->pScript, sbcl_to_string(NCR_700_readb(host, SBCL_REG)));
#endif
resume_offset = hostdata->pScript + Ent_SendMessagePhaseMismatch;
- } else if(dsp >= to32bit(&slot->pSG[0].ins) &&
+ } else if (slot && dsp >= to32bit(&slot->pSG[0].ins) &&
dsp <= to32bit(&slot->pSG[NCR_700_SG_SEGMENTS].ins)) {
int data_transfer = NCR_700_readl(host, DBC_REG) & 0xffffff;
int SGcount = (dsp - to32bit(&slot->pSG[0].ins))/sizeof(struct NCR_700_SG_List);
--
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