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| author | Xiaomeng Tong <xiam0nd.tong@gmail.com> | 2022-04-14 14:21:03 +0800 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-05-18 23:31:35 +1000 |
| commit | 300981abddcb13f8f06ad58f52358b53a8096775 (patch) | |
| tree | c63a5d60a31097ba4e18d34a2bd1906f67b43398 | |
| parent | d53c36e6c83863fde4a2748411c31bc4853a0936 (diff) | |
| download | lwn-300981abddcb13f8f06ad58f52358b53a8096775.tar.gz lwn-300981abddcb13f8f06ad58f52358b53a8096775.zip | |
KVM: PPC: Book3S HV: fix incorrect NULL check on list iterator
The bug is here:
if (!p)
return ret;
The list iterator value 'p' will *always* be set and non-NULL by
list_for_each_entry(), so it is incorrect to assume that the iterator
value will be NULL if the list is empty or no element is found.
To fix the bug, Use a new value 'iter' as the list iterator, while use
the old value 'p' as a dedicated variable to point to the found element.
Fixes: dfaa973ae960 ("KVM: PPC: Book3S HV: In H_SVM_INIT_DONE, migrate remaining normal-GFNs to secure-GFNs")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220414062103.8153-1-xiam0nd.tong@gmail.com
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_uvmem.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 45c993dd05f5..36f2314c58e5 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -361,13 +361,15 @@ static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm, static bool kvmppc_next_nontransitioned_gfn(const struct kvm_memory_slot *memslot, struct kvm *kvm, unsigned long *gfn) { - struct kvmppc_uvmem_slot *p; + struct kvmppc_uvmem_slot *p = NULL, *iter; bool ret = false; unsigned long i; - list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) - if (*gfn >= p->base_pfn && *gfn < p->base_pfn + p->nr_pfns) + list_for_each_entry(iter, &kvm->arch.uvmem_pfns, list) + if (*gfn >= iter->base_pfn && *gfn < iter->base_pfn + iter->nr_pfns) { + p = iter; break; + } if (!p) return ret; /* |