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authorAlan Stern <stern@rowland.harvard.edu>2013-09-06 11:49:51 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-09-26 16:52:45 -0700
commit173798ef2abbec8faf2a4397a24bd357fecfe008 (patch)
tree0febb096989c635fa05ed104b0c8e2b5487cc6b1
parent04b25c9dde9337ea972147f47fa75709dd7377f3 (diff)
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SCSI: 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 3d15a37c4daa..cc3943a0ab57 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2135,14 +2135,9 @@ 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);