TLDRVuln - Cybersecurity Vulnerabilities Made Simple

In the Linux kernel, the following vulnerability has been resolved:

iavf: fix hang on reboot with ice

When a system with E810 with existing VFs gets rebooted the following

hang may be observed.

Pid 1 is hung in iavf_remove(), part of a network driver:

PID: 1 TASK: ffff965400e5a340 CPU: 24 COMMAND: "systemd-shutdow"

#0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb

#1 [ffffaad04005fae8] schedule at ffffffff8b323e2d

#2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc

#3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930

#4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf]

#5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513

#6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa

#7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc

#8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e

#9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429

#10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4

#11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice]

#12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice]

#13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice]

#14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1

#15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386

#16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870

#17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6

#18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159

#19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc

#20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d

#21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169

#22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b

RIP: 00007f1baa5c13d7 RSP: 00007fffbcc55a98 RFLAGS: 00000202

RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1baa5c13d7

RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead

RBP: 00007fffbcc55ca0 R8: 0000000000000000 R9: 00007fffbcc54e90

R10: 00007fffbcc55050 R11: 0000000000000202 R12: 0000000000000005

R13: 0000000000000000 R14: 00007fffbcc55af0 R15: 0000000000000000

ORIG_RAX: 00000000000000a9 CS: 0033 SS: 002b

During reboot all drivers PM shutdown callbacks are invoked.

In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE.

In ice_shutdown() the call chain above is executed, which at some point

calls iavf_remove(). However iavf_remove() expects the VF to be in one

of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If

that's not the case it sleeps forever.

So if iavf_shutdown() gets invoked before iavf_remove() the system will

hang indefinitely because the adapter is already in state __IAVF_REMOVE.

Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE,

as we already went through iavf_shutdown().