KVM: PPC: Book3S: Suppress warnings when allocating too big memory slots

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The userspace can trigger "vmalloc size %lu allocation failure: exceeds
total pages" via the KVM_SET_USER_MEMORY_REGION ioctl.

This silences the warning by checking the limit before calling vzalloc()
and returns ENOMEM if failed.

This does not call underlying valloc helpers as __vmalloc_node() is only
exported when CONFIG_TEST_VMALLOC_MODULE and __vmalloc_node_range() is
not exported at all.

Spotted by syzkaller.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[mpe: Use 'size' for the variable rather than 'cb']
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210901084512.1658628-1-aik@ozlabs.ru

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Alexey Kardashevskiy 2021-09-01 18:45:12 +10:00 • committed by Michael Ellerman

parent f6a1987773

commit 511d25d6b7

1 changed files with 6 additions and 2 deletions

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arch/powerpc/kvm/book3s_hv.c

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