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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] x86/mm: Add array_index_nospec to guest provided index values
commit 5160dbd512523d865f7271af23636aa3f3536186
Author: Alexandru Stefan ISAILA <aisaila@xxxxxxxxxxxxxxx>
AuthorDate: Fri Jan 17 13:31:26 2020 +0000
Commit: George Dunlap <george.dunlap@xxxxxxxxxx>
CommitDate: Thu Jan 23 14:24:55 2020 +0000
x86/mm: Add array_index_nospec to guest provided index values
This patch aims to sanitize indexes, potentially guest provided
values, for altp2m_eptp[] and altp2m_p2m[] arrays.
Requested-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Alexandru Isaila <aisaila@xxxxxxxxxxxxxxx>
Acked-by: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>
---
xen/arch/x86/mm/mem_access.c | 21 ++++++++++++---------
xen/arch/x86/mm/p2m-ept.c | 4 ++--
xen/arch/x86/mm/p2m.c | 39 +++++++++++++++++++++++----------------
3 files changed, 37 insertions(+), 27 deletions(-)
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index 320b9fe621..31ff826393 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 = array_access_nospec(d->arch.altp2m_p2m, altp2m_idx);
}
#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 = array_access_nospec(d->arch.altp2m_p2m, altp2m_idx);
}
#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 = array_access_nospec(d->arch.altp2m_p2m, altp2m_idx);
}
#else
ASSERT(!altp2m_idx);
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index b5517769c9..b078a9a59e 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -1353,7 +1353,7 @@ void setup_ept_dump(void)
void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
{
- struct p2m_domain *p2m = d->arch.altp2m_p2m[i];
+ struct p2m_domain *p2m = array_access_nospec(d->arch.altp2m_p2m, i);
struct p2m_domain *hostp2m = p2m_get_hostp2m(d);
struct ept_data *ept;
@@ -1366,7 +1366,7 @@ void p2m_init_altp2m_ept(struct domain *d, unsigned int i)
p2m->max_mapped_pfn = p2m->max_remapped_gfn = 0;
ept = &p2m->ept;
ept->mfn = pagetable_get_pfn(p2m_get_pagetable(p2m));
- d->arch.altp2m_eptp[i] = ept->eptp;
+ d->arch.altp2m_eptp[array_index_nospec(i, MAX_EPTP)] = ept->eptp;
}
unsigned int p2m_find_altp2m_by_eptp(struct domain *d, uint64_t eptp)
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 3119269073..00b24342fc 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2502,7 +2502,7 @@ static void p2m_reset_altp2m(struct domain *d, unsigned
int idx,
struct p2m_domain *p2m;
ASSERT(idx < MAX_ALTP2M);
- p2m = d->arch.altp2m_p2m[idx];
+ p2m = array_access_nospec(d->arch.altp2m_p2m, idx);
p2m_lock(p2m);
@@ -2543,7 +2543,7 @@ static int p2m_activate_altp2m(struct domain *d, unsigned
int idx)
ASSERT(idx < MAX_ALTP2M);
- p2m = d->arch.altp2m_p2m[idx];
+ p2m = array_access_nospec(d->arch.altp2m_p2m, idx);
hostp2m = p2m_get_hostp2m(d);
p2m_lock(p2m);
@@ -2574,12 +2574,13 @@ int p2m_init_altp2m_by_id(struct domain *d, unsigned
int idx)
{
int rc = -EINVAL;
- if ( idx >= MAX_ALTP2M )
+ if ( idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) )
return rc;
altp2m_list_lock(d);
- if ( d->arch.altp2m_eptp[idx] == mfn_x(INVALID_MFN) )
+ if ( d->arch.altp2m_eptp[array_index_nospec(idx, MAX_EPTP)] ==
+ mfn_x(INVALID_MFN) )
rc = p2m_activate_altp2m(d, idx);
altp2m_list_unlock(d);
@@ -2615,7 +2616,7 @@ int p2m_destroy_altp2m_by_id(struct domain *d, unsigned
int idx)
struct p2m_domain *p2m;
int rc = -EBUSY;
- if ( !idx || idx >= MAX_ALTP2M )
+ if ( !idx || idx >= min(ARRAY_SIZE(d->arch.altp2m_p2m), MAX_EPTP) )
return rc;
rc = domain_pause_except_self(d);
@@ -2625,14 +2626,16 @@ int p2m_destroy_altp2m_by_id(struct domain *d, unsigned
int idx)
rc = -EBUSY;
altp2m_list_lock(d);
- if ( d->arch.altp2m_eptp[idx] != mfn_x(INVALID_MFN) )
+ if ( d->arch.altp2m_eptp[array_index_nospec(idx, MAX_EPTP)] !=
+ mfn_x(INVALID_MFN) )
{
- p2m = d->arch.altp2m_p2m[idx];
+ p2m = array_access_nospec(d->arch.altp2m_p2m, idx);
if ( !_atomic_read(p2m->active_vcpus) )
{
p2m_reset_altp2m(d, idx, ALTP2M_DEACTIVATE);
- d->arch.altp2m_eptp[idx] = mfn_x(INVALID_MFN);
+ d->arch.altp2m_eptp[array_index_nospec(idx, MAX_EPTP)] =
+ mfn_x(INVALID_MFN);
rc = 0;
}
}
@@ -2689,11 +2692,13 @@ 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 = array_access_nospec(d->arch.altp2m_p2m, idx);
p2m_lock(hp2m);
p2m_lock(ap2m);
@@ -3032,11 +3037,12 @@ 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 = array_access_nospec(d->arch.altp2m_p2m, altp2m_idx);
}
else
p2m = host_p2m;
@@ -3075,11 +3081,12 @@ 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 = array_access_nospec(d->arch.altp2m_p2m, altp2m_idx);
}
else
p2m = host_p2m;
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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