Peter Schneider reported that a system would no longer boot after
updating to 6.8.4. Peter bisected the issue and identified commit
b5fc07a5fb56 ("scsi: core: Consult supported VPD page list prior to
fetching page") as being the culprit.
Turns out the enclosure device in Peter's system reports a byteswapped
page length for VPD page 0. It reports "02 00" as page length instead
of "00 02". This causes us to attempt to access 516 bytes (page length
+ header) of information despite only 2 pages being present.
Limit the page search scope to the size of our VPD buffer to guard
against devices returning a larger page count than requested.
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Peter Schneider <pschneider1968@xxxxxxxxxxxxxx>
Tested-by: Peter Schneider <pschneider1968@xxxxxxxxxxxxxx>
Fixes: b5fc07a5fb56 ("scsi: core: Consult supported VPD page list prior to fetching page")
Link: https://lore.kernel.org/all/eec6ebbf-061b-4a7b-96dc-ea748aa4d035@xxxxxxxxxxxxxx/
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
drivers/scsi/scsi.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 3e0c0381277a..f0464db3f9de 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -350,6 +350,13 @@ static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
if (result < SCSI_VPD_HEADER_SIZE)
return 0;
+ if (result > sizeof(vpd)) {
+ dev_warn_once(&sdev->sdev_gendev,
+ "%s: long VPD page 0 length: %d bytes\n",
+ __func__, result);
+ result = sizeof(vpd);
+ }
+
result -= SCSI_VPD_HEADER_SIZE;
if (!memchr(&vpd[SCSI_VPD_HEADER_SIZE], page, result))
return 0;
--
2.44.0
