1. 04 Jul, 2023 2 commits
    • Petr Pavlu's avatar
      xen/virtio: Fix NULL deref when a bridge of PCI root bus has no parent · 21a235bc
      Petr Pavlu authored
      When attempting to run Xen on a QEMU/KVM virtual machine with virtio
      devices (all x86_64), function xen_dt_get_node() crashes on accessing
      bus->bridge->parent->of_node because a bridge of the PCI root bus has no
      parent set:
      
      [    1.694192][    T1] BUG: kernel NULL pointer dereference, address: 0000000000000288
      [    1.695688][    T1] #PF: supervisor read access in kernel mode
      [    1.696297][    T1] #PF: error_code(0x0000) - not-present page
      [    1.696297][    T1] PGD 0 P4D 0
      [    1.696297][    T1] Oops: 0000 [#1] PREEMPT SMP NOPTI
      [    1.696297][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.3.7-1-default #1 openSUSE Tumbleweed a577eae57964bb7e83477b5a5645a1781df990f0
      [    1.696297][    T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
      [    1.696297][    T1] RIP: e030:xen_virtio_restricted_mem_acc+0xd9/0x1c0
      [    1.696297][    T1] Code: 45 0c 83 e8 c9 a3 ea ff 31 c0 eb d7 48 8b 87 40 ff ff ff 48 89 c2 48 8b 40 10 48 85 c0 75 f4 48 8b 82 10 01 00 00 48 8b 40 40 <48> 83 b8 88 02 00 00 00 0f 84 45 ff ff ff 66 90 31 c0 eb a5 48 89
      [    1.696297][    T1] RSP: e02b:ffffc90040013cc8 EFLAGS: 00010246
      [    1.696297][    T1] RAX: 0000000000000000 RBX: ffff888006c75000 RCX: 0000000000000029
      [    1.696297][    T1] RDX: ffff888005ed1000 RSI: ffffc900400f100c RDI: ffff888005ee30d0
      [    1.696297][    T1] RBP: ffff888006c75010 R08: 0000000000000001 R09: 0000000330000006
      [    1.696297][    T1] R10: ffff888005850028 R11: 0000000000000002 R12: ffffffff830439a0
      [    1.696297][    T1] R13: 0000000000000000 R14: ffff888005657900 R15: ffff888006e3e1e8
      [    1.696297][    T1] FS:  0000000000000000(0000) GS:ffff88804a000000(0000) knlGS:0000000000000000
      [    1.696297][    T1] CS:  e030 DS: 0000 ES: 0000 CR0: 0000000080050033
      [    1.696297][    T1] CR2: 0000000000000288 CR3: 0000000002e36000 CR4: 0000000000050660
      [    1.696297][    T1] Call Trace:
      [    1.696297][    T1]  <TASK>
      [    1.696297][    T1]  virtio_features_ok+0x1b/0xd0
      [    1.696297][    T1]  virtio_dev_probe+0x19c/0x270
      [    1.696297][    T1]  really_probe+0x19b/0x3e0
      [    1.696297][    T1]  __driver_probe_device+0x78/0x160
      [    1.696297][    T1]  driver_probe_device+0x1f/0x90
      [    1.696297][    T1]  __driver_attach+0xd2/0x1c0
      [    1.696297][    T1]  bus_for_each_dev+0x74/0xc0
      [    1.696297][    T1]  bus_add_driver+0x116/0x220
      [    1.696297][    T1]  driver_register+0x59/0x100
      [    1.696297][    T1]  virtio_console_init+0x7f/0x110
      [    1.696297][    T1]  do_one_initcall+0x47/0x220
      [    1.696297][    T1]  kernel_init_freeable+0x328/0x480
      [    1.696297][    T1]  kernel_init+0x1a/0x1c0
      [    1.696297][    T1]  ret_from_fork+0x29/0x50
      [    1.696297][    T1]  </TASK>
      [    1.696297][    T1] Modules linked in:
      [    1.696297][    T1] CR2: 0000000000000288
      [    1.696297][    T1] ---[ end trace 0000000000000000 ]---
      
      The PCI root bus is in this case created from ACPI description via
      acpi_pci_root_add() -> pci_acpi_scan_root() -> acpi_pci_root_create() ->
      pci_create_root_bus() where the last function is called with
      parent=NULL. It indicates that no parent is present and then
      bus->bridge->parent is NULL too.
      
      Fix the problem by checking bus->bridge->parent in xen_dt_get_node() for
      NULL first.
      
      Fixes: ef8ae384 ("xen/virtio: Handle PCI devices which Host controller is described in DT")
      Signed-off-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
      Reviewed-by: default avatarOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
      Reviewed-by: default avatarStefano Stabellini <sstabellini@kernel.org>
      Link: https://lore.kernel.org/r/20230621131214.9398-2-petr.pavlu@suse.comSigned-off-by: default avatarJuergen Gross <jgross@suse.com>
      21a235bc
    • Jan Beulich's avatar
      x86/Xen: tidy xen-head.S · 1cfd4ccb
      Jan Beulich authored
      First of all move PV-only ELF notes inside the XEN_PV conditional; note
      that
      - HV_START_LOW is dropped altogether, as it was meaningful for 32-bit PV
        only,
      - the 32-bit instance of VIRT_BASE is dropped, as it would be dead code
        once inside the conditional,
      - while PADDR_OFFSET is not exactly unused for PVH, it defaults to zero
        there, and the hypervisor (or tool stack) complains if it is present
        but VIRT_BASE isn't.
      Then have the "supported features" note actually report reality: All
      three of the features there are supported and/or applicable only in
      certain cases.
      Signed-off-by: default avatarJan Beulich <jbeulich@suse.com>
      Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
      Link: https://lore.kernel.org/r/f99bacc6-2a2f-41b0-5c0b-e01b7051cb07@suse.comSigned-off-by: default avatarJuergen Gross <jgross@suse.com>
      1cfd4ccb
  2. 26 Jun, 2023 4 commits
  3. 25 Jun, 2023 5 commits
  4. 23 Jun, 2023 21 commits
  5. 22 Jun, 2023 8 commits