diff options
| author | Alexey Kardashevskiy <aik@ozlabs.ru> | 2021-09-01 18:45:12 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-12-02 22:55:10 +1100 |
| commit | 511d25d6b789fffcb20a3eb71899cf974a31bd9d (patch) | |
| tree | 3e5d069aba8feee9036443b4191a63a69fd6d89e /arch/powerpc/kvm | |
| parent | f6a1987773a5908bae7bcadbeec0bcab25df7b20 (diff) | |
KVM: PPC: Book3S: Suppress warnings when allocating too big memory slots
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
Diffstat (limited to 'arch/powerpc/kvm')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 98e90bdf1f27..7986911b873c 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -4872,8 +4872,12 @@ static int kvmppc_core_prepare_memory_region_hv(struct kvm *kvm, unsigned long npages = mem->memory_size >> PAGE_SHIFT; if (change == KVM_MR_CREATE) { - slot->arch.rmap = vzalloc(array_size(npages, - sizeof(*slot->arch.rmap))); + unsigned long size = array_size(npages, sizeof(*slot->arch.rmap)); + + if ((size >> PAGE_SHIFT) > totalram_pages()) + return -ENOMEM; + + slot->arch.rmap = vzalloc(size); if (!slot->arch.rmap) return -ENOMEM; } |