This patch aims to sanitize indexes, potentially guest provided
values, for altp2m_eptp[] and altp2m_p2m[] arrays.
Requested-by: Jan Beulich <jbeul...@suse.com>
Signed-off-by: Alexandru Isaila <aisa...@bitdefender.com>
---
CC: Razvan Cojocaru <rcojoc...@bitdefender.com>
CC: Tamas K Lengyel <ta...@tklengyel.com>
CC: Petre Pircalabu <ppircal...@bitdefender.com>
CC: George Dunlap <george.dun...@eu.citrix.com>
CC: Jan Beulich <jbeul...@suse.com>
CC: Andrew Cooper <andrew.coop...@citrix.com>
CC: Wei Liu <w...@xen.org>
CC: "Roger Pau Monné" <roger....@citrix.com>
CC: Jun Nakajima <jun.nakaj...@intel.com>
CC: Kevin Tian <kevin.t...@intel.com>
---
Changes since V5:
- Add black lines
- Check altp2m_idx against min(ARRAY_SIZE(d->arch.altp2m_p2m),
MAX_EPTP).
---
xen/arch/x86/mm/mem_access.c | 21 ++++++++++++---------
xen/arch/x86/mm/p2m.c | 26 ++++++++++++++++++--------
2 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index 320b9fe621..a95a50bcae 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -366,11 +366,12 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn,
uint32_t nr,
#ifdef CONFIG_HVM
if ( altp2m_idx )
{
- if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ if ( altp2m_idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) ||
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
return -EINVAL;
- ap2m = d->arch.altp2m_p2m[altp2m_idx];
+ ap2m = d->arch.altp2m_p2m[array_index_nospec(altp2m_idx, MAX_ALTP2M)];
}
#else
ASSERT(!altp2m_idx);
@@ -425,11 +426,12 @@ long p2m_set_mem_access_multi(struct domain *d,
#ifdef CONFIG_HVM
if ( altp2m_idx )
{
- if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ if ( altp2m_idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) ||
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
return -EINVAL;
- ap2m = d->arch.altp2m_p2m[altp2m_idx];
+ ap2m = d->arch.altp2m_p2m[array_index_nospec(altp2m_idx, MAX_ALTP2M)];
}
#else
ASSERT(!altp2m_idx);
@@ -491,11 +493,12 @@ int p2m_get_mem_access(struct domain *d, gfn_t gfn,
xenmem_access_t *access,
}
else if ( altp2m_idx ) /* altp2m view 0 is treated as the hostp2m */
{
- if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ if ( altp2m_idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) ||
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
return -EINVAL;
- p2m = d->arch.altp2m_p2m[altp2m_idx];
+ p2m = d->arch.altp2m_p2m[array_index_nospec(altp2m_idx, MAX_ALTP2M)];
}
#else
ASSERT(!altp2m_idx);
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 3119269073..4fc919a9c5 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2577,6 +2577,8 @@ int p2m_init_altp2m_by_id(struct domain *d, unsigned int
idx)
if ( idx >= MAX_ALTP2M )
return rc;
+ idx = array_index_nospec(idx, MAX_ALTP2M);
+
altp2m_list_lock(d);
if ( d->arch.altp2m_eptp[idx] == mfn_x(INVALID_MFN) )
@@ -2618,6 +2620,8 @@ int p2m_destroy_altp2m_by_id(struct domain *d, unsigned
int idx)
if ( !idx || idx >= MAX_ALTP2M )
return rc;
+ idx = array_index_nospec(idx, MAX_ALTP2M);
+
rc = domain_pause_except_self(d);
if ( rc )
return rc;
@@ -2689,11 +2693,13 @@ int p2m_change_altp2m_gfn(struct domain *d, unsigned
int idx,
mfn_t mfn;
int rc = -EINVAL;
- if ( idx >= MAX_ALTP2M || d->arch.altp2m_eptp[idx] == mfn_x(INVALID_MFN) )
+ if ( idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) ||
+ d->arch.altp2m_eptp[array_index_nospec(idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
return rc;
hp2m = p2m_get_hostp2m(d);
- ap2m = d->arch.altp2m_p2m[idx];
+ ap2m = d->arch.altp2m_p2m[array_index_nospec(idx, MAX_ALTP2M)];
p2m_lock(hp2m);
p2m_lock(ap2m);
@@ -3032,11 +3038,13 @@ int p2m_set_suppress_ve(struct domain *d, gfn_t gfn,
bool suppress_ve,
if ( altp2m_idx > 0 )
{
- if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ if ( altp2m_idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) ||
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
return -EINVAL;
- p2m = ap2m = d->arch.altp2m_p2m[altp2m_idx];
+ p2m = ap2m = d->arch.altp2m_p2m[array_index_nospec(altp2m_idx,
+ MAX_ALTP2M)];
}
else
p2m = host_p2m;
@@ -3075,11 +3083,13 @@ int p2m_get_suppress_ve(struct domain *d, gfn_t gfn,
bool *suppress_ve,
if ( altp2m_idx > 0 )
{
- if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ if ( altp2m_idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) ||
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
return -EINVAL;
- p2m = ap2m = d->arch.altp2m_p2m[altp2m_idx];
+ p2m = ap2m = d->arch.altp2m_p2m[array_index_nospec(altp2m_idx,
+ MAX_ALTP2M)];
}
else
p2m = host_p2m;
--
2.17.1
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