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authorAlan Stern <stern@rowland.harvard.edu>2013-09-06 11:49:51 -0400
committerBen Hutchings <ben@decadent.org.uk>2013-10-26 21:06:03 +0100
commit268dbe7b8b328bf8e9960a8f7e70080cf4eb219d (patch)
treeaaeb7c101b80cde206470a9125cd283a9d672d4d /drivers
parent1d7af96c344aff74a021d39c0c9063b15bda522c (diff)
sd: Fix potential out-of-bounds access
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@rowland.harvard.edu> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/sd.c11
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 17603daf9b57..f6d2b62ec005 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2136,14 +2136,9 @@ 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);