Commit 04631f55 authored by Ranjan Kumar's avatar Ranjan Kumar Committed by Martin K. Petersen
Browse files

scsi: mpt3sas: Limit NVMe request size to 2 MiB 



The HBA firmware reports NVMe MDTS values based on the underlying drive
capability. However, because the driver allocates a fixed 4K buffer for
the PRP list, accommodating at most 512 entries, the driver supports a
maximum I/O transfer size of 2 MiB.

Limit max_hw_sectors to the smaller of the reported MDTS and the 2 MiB
driver limit to prevent issuing oversized I/O that may lead to a kernel
oops.

Cc: stable@vger.kernel.org
Fixes: 9b8b8487 ("block: Increase BLK_DEF_MAX_SECTORS_CAP")
Reported-by: default avatarMira Limbeck <m.limbeck@proxmox.com>
Closes: https://lore.kernel.org/r/291f78bf-4b4a-40dd-867d-053b36c564b3@proxmox.com
Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9b8b84879d4a


Suggested-by: default avatarKeith Busch <kbusch@kernel.org>
Signed-off-by: default avatarRanjan Kumar <ranjan.kumar@broadcom.com>
Tested-by: default avatarMira Limbeck <m.limbeck@proxmox.com>
Link: https://patch.msgid.link/20260414110811.85156-1-ranjan.kumar@broadcom.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 7b03c93d

drivers/scsi/mpt3sas/mpt3sas_scsih.c

+13 −1
Original line number Diff line number Diff line
@@ -2738,8 +2738,20 @@ scsih_sdev_configure(struct scsi_device *sdev, struct queue_limits *lim) 
				pcie_device->enclosure_level,

				pcie_device->connector_name);



		/*

		 * The HBA firmware passes the NVMe drive's MDTS

		 * (Maximum Data Transfer Size) up to the driver. However,

		 * the driver hardcodes a 4K buffer size for the PRP list,

		 * accommodating at most 512 entries. This strictly limits

		 * the maximum supported NVMe I/O transfer to 2 MiB.

		 *

		 * Cap max_hw_sectors to the smaller of the drive's reported

		 * MDTS or the 2 MiB driver limit to prevent kernel oopses.

		 */

		lim->max_hw_sectors = SZ_2M >> SECTOR_SHIFT;

		if (pcie_device->nvme_mdts)

			lim->max_hw_sectors = pcie_device->nvme_mdts / 512;

			lim->max_hw_sectors = min(lim->max_hw_sectors,

					pcie_device->nvme_mdts >> SECTOR_SHIFT);



		pcie_device_put(pcie_device);

		spin_unlock_irqrestore(&ioc->pcie_device_lock, flags);