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authorAlan Stern <stern@rowland.harvard.edu>2013-09-06 11:49:51 -0400
committerJames Bottomley <JBottomley@Parallels.com>2013-09-11 09:44:00 -0700
commit984f1733fcee3fbc78d47e26c5096921c5d9946a (patch)
tree2f36698d0e3a90f653d5c6673c2144b3530cb1c6 /drivers/scsi/sd.c
parent76c4f79d909623ea144262626428a2dfb54b40e3 (diff)
[SCSI] sd: Fix potential out-of-bounds access
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> CC: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'drivers/scsi/sd.c')
-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 b58e8f815a0..e62d17d41d4 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2420,14 +2420,9 @@ 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);