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scsi: core: Handle devices which return an unusually large VPD page count

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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.

Link: https://lore.kernel.org/r/20240521023040.2703884-1-martin.petersen@oracle.com
Fixes: b5fc07a5fb56 ("scsi: core: Consult supported VPD page list prior to fetching page")
Cc: stable@vger.kernel.org
Reported-by: Peter Schneider <pschneider1968@googlemail.com>
Closes: https://lore.kernel.org/all/eec6ebbf-061b-4a7b-96dc-ea748aa4d035@googlemail.com/
Tested-by: Peter Schneider <pschneider1968@googlemail.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Martin K. Petersen 2024-05-20 22:30:40 -04:00
parent e4f5f8298c
commit d09c05aa35
1 changed files with 7 additions and 0 deletions
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7
drivers/scsi/scsi.c
View File

@ -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;