lshw incorrectly detects frame buffer devices

[Robert Malz]

[ Impact ]

 * Executing lshw can provide incorrect output for devices if frame buffer (fb) devices are present in the system.

 * Issue happens when lshw parses fb devices, internally it tries to look for a PCI device which matches a set of requirements (it's looking for iommu address ranges for device based on data from FB device IOCTL). If a device is matched it will append it's metadata to it and later print it.
Problem is in logic used to detect fb devices metadata. As a result the first device on the list with iommu resource can be correlated with fb device.

 * In following example, fb metadata has been added to network adapter.
        *-network:0
             description: Ethernet interface
             product: Ethernet Controller XXV710 for 25GbE SFP28
             vendor: Intel Corporation
             physical id: 0
             bus info: pci@0000:5e:00.0
             logical name: enp94s0f0
             logical name: /dev/fb0
             version: 02
             serial: 50:7c:6f:45:ca:23
             capacity: 25Gbit/s
             width: 64 bits
             clock: 33MHz
             capabilities: pm msi msix pciexpress vpd bus_master cap_list rom ethernet physical fibre 25000bt-fd autonegotiation fb
             configuration: autonegotiation=off broadcast=yes depth=32 driver=i40e driverversion=5.15.0-107-generic duplex=full firmware=9.50 0x8000f251 23.0.8 latency=0 link=yes mode=1024x768 multicast=yes slave=yes visual=truecolor xres=1024 yres=768
             resources: iomemory:38c00-38bff iomemory:38c00-38bff irq:36 memory:38c000000000-38c000ffffff memory:38c002800000-38c002807fff memory:b8800000-b887ffff memory:38c002000000-38c0023fffff memory:38c002810000-38c00290ffff

 * More discussion on the issue in [0]

[ Test Plan ]

 * FB (/dev/fb0) device is required to reproduce the issue, then run "lshw" and check output of all devices.

In my local local laptop fb data is added to 3D controller device:
           *-display
                description: 3D controller
                product: NVIDIA Corporation
                vendor: NVIDIA Corporation
                physical id: 0
                bus info: pci@0000:01:00.0
                logical name: /dev/fb0
                version: a1
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress bus_master cap_list rom fb
                configuration: depth=32 driver=nvidia latency=0 mode=1920x1200 visual=truecolor xres=1920 yres=1200
                resources: iomemory:600-5ff iomemory:620-61f irq:180 memory:be000000-beffffff memory:6000000000-61ffffffff memory:6200000000-6201ffffff ioport:3000(size=128)
        *-display
             description: VGA compatible controller
             product: Intel Corporation
             vendor: Intel Corporation
             physical id: 2
             bus info: pci@0000:00:02.0
             logical name: /dev/fb0
             version: 04
             width: 64 bits
             clock: 33MHz
             capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
             configuration: depth=32 driver=i915 latency=0 resolution=1920,1200

With fix:
           *-display
                description: 3D controller
                product: NVIDIA Corporation
                vendor: NVIDIA Corporation
                physical id: 0
                bus info: pci@0000:01:00.0
                version: a1
                width: 64 bits
                clock: 33MHz
                capabilities: pm msi pciexpress bus_master cap_list rom
                configuration: driver=nvidia latency=0
                resources: iomemory:600-5ff iomemory:620-61f irq:180 memory:be000000-beffffff memory:6000000000-61ffffffff memory:6200000000-6201ffffff ioport:3000(size=128)
        *-display
             description: VGA compatible controller
             product: Intel Corporation
             vendor: Intel Corporation
             physical id: 2
             bus info: pci@0000:00:02.0
             logical name: /dev/fb0
             version: 04
             width: 64 bits
             clock: 33MHz
             capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
             configuration: depth=32 driver=i915 latency=0 mode=1920x1200 visual=truecolor xres=1920 yres=1200
             resources: iomemory:620-61f iomemory:400-3ff irq:181 memory:6288000000-6288ffffff memory:4000000000-400fffffff ioport:4000(size=64) memory:c0000-dffff memory:4010000000-4016ffffff memory:4020000000-40ffffffff

[ Where problems could occur ]

 * Fix is written in a way that if new way of detecting fb metadata does not work it will fall back to previous method.

 * Worst case scenario is that fb data will not be printed

[ Other Info ]

 * To workaround the problem disable fb detection by adding -disable fb

 * Upstream patches [1]

[0] - https://github.com/lyonel/lshw/pull/106
[1] - https://ezix.org/src/pkg/lshw/commits/branch/master af7c69e1b6 8798c9f1a2

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "focal debdiff" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Robert Malz (rmalz)]

resolute debdiff

[Simon Chopin (schopin)]

Hi,

Thanks for the patches!

Please note that typically we wouldn't upload the fix to Focal, as it is out of standard support.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.