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| author | Xiao Guangrong <[email protected]> | 2012-10-24 06:07:59 +0000 |
|---|---|---|
| committer | Marcelo Tosatti <[email protected]> | 2012-10-31 22:36:30 +0000 |
| commit | 87da7e66a40532b743cd50972fcf85a1f15b14ea (patch) | |
| tree | e553258648881176136774013f0fecff876644bb /security/selinux/netnode.c | |
| parent | Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sag... (diff) | |
| download | kernel-87da7e66a40532b743cd50972fcf85a1f15b14ea.tar.gz kernel-87da7e66a40532b743cd50972fcf85a1f15b14ea.zip | |
KVM: x86: fix vcpu->mmio_fragments overflow
After commit b3356bf0dbb349 (KVM: emulator: optimize "rep ins" handling),
the pieces of io data can be collected and write them to the guest memory
or MMIO together
Unfortunately, kvm splits the mmio access into 8 bytes and store them to
vcpu->mmio_fragments. If the guest uses "rep ins" to move large data, it
will cause vcpu->mmio_fragments overflow
The bug can be exposed by isapc (-M isapc):
[23154.818733] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
[ ......]
[23154.858083] Call Trace:
[23154.859874] [<ffffffffa04f0e17>] kvm_get_cr8+0x1d/0x28 [kvm]
[23154.861677] [<ffffffffa04fa6d4>] kvm_arch_vcpu_ioctl_run+0xcda/0xe45 [kvm]
[23154.863604] [<ffffffffa04f5a1a>] ? kvm_arch_vcpu_load+0x17b/0x180 [kvm]
Actually, we can use one mmio_fragment to store a large mmio access then
split it when we pass the mmio-exit-info to userspace. After that, we only
need two entries to store mmio info for the cross-mmio pages access
Signed-off-by: Xiao Guangrong <[email protected]>
Signed-off-by: Marcelo Tosatti <[email protected]>
Diffstat (limited to 'security/selinux/netnode.c')
0 files changed, 0 insertions, 0 deletions