Am 21.05.2024 um 04:30 schrieb Martin K. Petersen:
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@vger.kernel.org Reported-by: Peter Schneider pschneider1968@googlemail.com Tested-by: Peter Schneider pschneider1968@googlemail.com Fixes: b5fc07a5fb56 ("scsi: core: Consult supported VPD page list prior to fetching page") Link: https://lore.kernel.org/all/eec6ebbf-061b-4a7b-96dc-ea748aa4d035@googlemail.... Signed-off-by: Martin K. Petersen martin.petersen@oracle.com
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;
I have built and tested Martin's patch against 6.8.4, 6.8.10, and 6.9.1, and it works fine and fixes my issue.
Tested-by: Peter Schneider pschneider1968@googlemail.com
In case anybody else is affected: The enclosure device in question with that buggy behaviour is that in a Supermicro 745BTQ-R920B server casing, with SAS/SATA Backplane "743 SAS BACKPLANE W/AMI MG9072", MG9072 being the controller chip by American Megatrends, Inc. according to the device documentation which can be found here:
https://www.supermicro.com/de/products/chassis/4u/745/sc745btq-r920b
Beste Grüße, Peter Schneider