linux-kernel - revert bab65e48cb064 PCI/MSI Sanitize MSI-X checks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <caca6879210940428e0aa2a1496907ab@AcuMS.aculab.com>
Date:   Thu, 6 Apr 2023 11:05:14 +0000
From:   David Laight <David.Laight@...LAB.COM>
To:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Thomas Gleixner" <tglx@...utronix.de>,
        Jason Gunthorpe <jgg@...dia.com>,
        "Bjorn Helgaas" <bhelgaas@...gle.com>
CC:     Linus Torvalds <torvalds@...ux-foundation.org>,
        Christoph Hellwig <hch@...radead.org>
Subject: revert bab65e48cb064 PCI/MSI Sanitize MSI-X checks

The change in bab65e48cb064 breaks pci_enable_msix_range().
The intent is to optimise the sanity checks, but it is
somewhat overenthusiastic.

The interface allows you to ask for a lot of vectors and
returns the number that were allocated.
However, after the change, you can't request a vector
that is higher than the largest the hardware supports.
Which makes that rather pointless.

So code like:
	for (i = 0; i < 16; i++)
		msix_tbl[i].entry = i;
	nvec = pci_enable_msix_range(dev, msix_tbl, 1, 16);
Now returns -22 if the hardware only supports 8 interrupts.

Previously it returned 8.

I can fix my driver, but I suspect that any code that relies
on a smaller number of vectors being returned is now broken.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)