[PATCH 0/1] Fix for LP: #1790480

[Kleber Sacilotto de Souza]

BugLink: https://bugs.launchpad.net/bugs/1790480

== SRU Justification ==
IBM is requesting a fix for the following issue found with NVMe devices on
s390x:

The trigger is a PCI function whose driver requests more interrupts than the
architectural maximum. Currently this is only possible with a machine that
supports 64 CPUs (or more) with a NVMe function attached. Note that the LPAR
does not have to use >=64 CPUs since the NVMe driver uses num_possible_cpus()
which is resolved to the machine maximum on s390 (since all CPUs are
hot-pluggable). The oops happens after the driver calls pci_alloc_irq_vectors
during device probing - so most likely the system will panic during boot.

The fix has been cc'ed to stable@, but hasn't been picked up for Bionic yet.

== Fix ==
866f3576a72b s390/pci: fix out of bounds access during irq setup

== Regression Potential ==
Low. Affects only s390x systems with more than 64 cpus and NVMe function
enabled.

== Test case ==
Boot the kernel in an affected environment.

Sebastian Ott (1):
  s390/pci: fix out of bounds access during irq setup

 arch/s390/pci/pci.c | 2 ++
 1 file changed, 2 insertions(+)

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2.17.1