[PATCH 88/93] [SCSI] sd: Fix potential out-of-bounds access

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



3.8.13.10 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

commit 984f1733fcee3fbc78d47e26c5096921c5d9946a upstream.

This patch fixes an out-of-bounds error in sd_read_cache_type(), found
by Google's AddressSanitizer tool.  When the loop ends, we know that
"offset" lies beyond the end of the data in the buffer, so no Caching
mode page was found.  In theory it may be present, but the buffer size
is limited to 512 bytes.

Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: James Bottomley <JBottomley@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 drivers/scsi/sd.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index a1dcdc3..bc108d2 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2421,14 +2421,9 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 			}
 		}
 
-		if (modepage == 0x3F) {
-			sd_printk(KERN_ERR, sdkp, "No Caching mode page "
-				  "present\n");
-			goto defaults;
-		} else if ((buffer[offset] & 0x3f) != modepage) {
-			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
-			goto defaults;
-		}
+		sd_printk(KERN_ERR, sdkp, "No Caching mode page found\n");
+		goto defaults;
+
 	Page_found:
 		if (modepage == 8) {
 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]