Commit fb4b4a05 authored by Erni Sri Satya Vennela's avatar Erni Sri Satya Vennela Committed by Jakub Kicinski
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net: mana: Use at least SZ_4K in doorbell ID range check 



mana_gd_ring_doorbell() accesses offsets up to DOORBELL_OFFSET_EQ
(0xFF8) + 8 bytes = 4KB within each doorbell page. A db_page_size
smaller than SZ_4K is fundamentally incompatible with the driver:
doorbell pages would overlap and the device cannot function correctly.

Validate db_page_size at the source and fail the
probe early if the value is below SZ_4K. This ensures the doorbell ID
range check in mana_gd_register_device() can rely on db_page_size
being valid.

Fixes: 89fe91c6 ("net: mana: hardening: Validate doorbell ID from GDMA_REGISTER_DEVICE response")
Signed-off-by: default avatarErni Sri Satya Vennela <ernis@linux.microsoft.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260325180423.1923060-1-ernis@linux.microsoft.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent b8f9410a

drivers/net/ethernet/microsoft/mana/gdma_main.c

+25 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <linux/debugfs.h>

#include <linux/module.h>

#include <linux/pci.h>

#include <linux/sizes.h>

#include <linux/utsname.h>

#include <linux/version.h>

#include <linux/msi.h>
@@ -46,6 +47,18 @@ static int mana_gd_init_pf_regs(struct pci_dev *pdev) 
	u64 sriov_base_off;



	gc->db_page_size = mana_gd_r32(gc, GDMA_PF_REG_DB_PAGE_SIZE) & 0xFFFF;



	/* mana_gd_ring_doorbell() accesses offsets up to DOORBELL_OFFSET_EQ

	 * (0xFF8) + 8 bytes = 4KB within each doorbell page, so the page

	 * size must be at least SZ_4K.

	 */

	if (gc->db_page_size < SZ_4K) {

		dev_err(gc->dev,

			"Doorbell page size %llu too small (min %u)\n",

			gc->db_page_size, SZ_4K);

		return -EPROTO;

	}



	gc->db_page_off = mana_gd_r64(gc, GDMA_PF_REG_DB_PAGE_OFF);



	/* Validate doorbell offset is within BAR0 */
@@ -73,6 +86,18 @@ static int mana_gd_init_vf_regs(struct pci_dev *pdev) 
	struct gdma_context *gc = pci_get_drvdata(pdev);



	gc->db_page_size = mana_gd_r32(gc, GDMA_REG_DB_PAGE_SIZE) & 0xFFFF;



	/* mana_gd_ring_doorbell() accesses offsets up to DOORBELL_OFFSET_EQ

	 * (0xFF8) + 8 bytes = 4KB within each doorbell page, so the page

	 * size must be at least SZ_4K.

	 */

	if (gc->db_page_size < SZ_4K) {

		dev_err(gc->dev,

			"Doorbell page size %llu too small (min %u)\n",

			gc->db_page_size, SZ_4K);

		return -EPROTO;

	}



	gc->db_page_off = mana_gd_r64(gc, GDMA_REG_DB_PAGE_OFFSET);



	/* Validate doorbell offset is within BAR0 */