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 V4:
- Change bounds check from MAX_EPTP to MAX_ALTP2M
- Move array_index_nospec() closer to the bounds check.
---
xen/arch/x86/mm/mem_access.c | 15 +++++++++------
xen/arch/x86/mm/p2m.c | 20 ++++++++++++++------
2 files changed, 23 insertions(+), 12 deletions(-)
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index 320b9fe621..33e379db8f 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -367,10 +367,11 @@ long p2m_set_mem_access(struct domain *d, gfn_t gfn,
uint32_t nr,
if ( altp2m_idx )
{
if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_ALTP2M)] ==
+ 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);
@@ -426,10 +427,11 @@ long p2m_set_mem_access_multi(struct domain *d,
if ( altp2m_idx )
{
if ( altp2m_idx >= MAX_ALTP2M ||
- d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_ALTP2M)] ==
+ 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);
@@ -492,10 +494,11 @@ 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) )
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_ALTP2M)] ==
+ 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 ba126f790a..16039c7a57 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2574,6 +2574,7 @@ 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) )
@@ -2615,6 +2616,7 @@ 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;
@@ -2686,11 +2688,13 @@ 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 >= MAX_ALTP2M ||
+ d->arch.altp2m_eptp[array_index_nospec(idx, MAX_ALTP2M)] ==
+ 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);
@@ -3030,10 +3034,12 @@ 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) )
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_ALTP2M)] ==
+ 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;
@@ -3073,10 +3079,12 @@ 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) )
+ d->arch.altp2m_eptp[array_index_nospec(altp2m_idx, MAX_ALTP2M)] ==
+ 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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