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-rw-r--r--system/xen/xsa/xsa410-4.16-06.patch255
1 files changed, 0 insertions, 255 deletions
diff --git a/system/xen/xsa/xsa410-4.16-06.patch b/system/xen/xsa/xsa410-4.16-06.patch
deleted file mode 100644
index 8c89eb32c7a4..000000000000
--- a/system/xen/xsa/xsa410-4.16-06.patch
+++ /dev/null
@@ -1,255 +0,0 @@
-From: Roger Pau Monné <roger.pau@citrix.com>
-Subject: x86/shadow: tolerate failure in shadow_prealloc()
-
-Prevent _shadow_prealloc() from calling BUG() when unable to fulfill
-the pre-allocation and instead return true/false. Modify
-shadow_prealloc() to crash the domain on allocation failure (if the
-domain is not already dying), as shadow cannot operate normally after
-that. Modify callers to also gracefully handle {_,}shadow_prealloc()
-failing to fulfill the request.
-
-Note this in turn requires adjusting the callers of
-sh_make_monitor_table() also to handle it returning INVALID_MFN.
-sh_update_paging_modes() is also modified to add additional error
-paths in case of allocation failure, some of those will return with
-null monitor page tables (and the domain likely crashed). This is no
-different that current error paths, but the newly introduced ones are
-more likely to trigger.
-
-The now added failure points in sh_update_paging_modes() also require
-that on some error return paths the previous structures are cleared,
-and thus monitor table is null.
-
-While there adjust the 'type' parameter type of shadow_prealloc() to
-unsigned int rather than u32.
-
-This is part of CVE-2022-33746 / XSA-410.
-
-Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
-Signed-off-by: Jan Beulich <jbeulich@suse.com>
-Acked-by: Tim Deegan <tim@xen.org>
-
---- a/xen/arch/x86/mm/shadow/common.c
-+++ b/xen/arch/x86/mm/shadow/common.c
-@@ -36,6 +36,7 @@
- #include <asm/flushtlb.h>
- #include <asm/shadow.h>
- #include <xen/numa.h>
-+#include <public/sched.h>
- #include "private.h"
-
- DEFINE_PER_CPU(uint32_t,trace_shadow_path_flags);
-@@ -928,14 +929,15 @@ static inline void trace_shadow_prealloc
-
- /* Make sure there are at least count order-sized pages
- * available in the shadow page pool. */
--static void _shadow_prealloc(struct domain *d, unsigned int pages)
-+static bool __must_check _shadow_prealloc(struct domain *d, unsigned int pages)
- {
- struct vcpu *v;
- struct page_info *sp, *t;
- mfn_t smfn;
- int i;
-
-- if ( d->arch.paging.shadow.free_pages >= pages ) return;
-+ if ( d->arch.paging.shadow.free_pages >= pages )
-+ return true;
-
- /* Shouldn't have enabled shadows if we've no vcpus. */
- ASSERT(d->vcpu && d->vcpu[0]);
-@@ -951,7 +953,8 @@ static void _shadow_prealloc(struct doma
- sh_unpin(d, smfn);
-
- /* See if that freed up enough space */
-- if ( d->arch.paging.shadow.free_pages >= pages ) return;
-+ if ( d->arch.paging.shadow.free_pages >= pages )
-+ return true;
- }
-
- /* Stage two: all shadow pages are in use in hierarchies that are
-@@ -974,7 +977,7 @@ static void _shadow_prealloc(struct doma
- if ( d->arch.paging.shadow.free_pages >= pages )
- {
- guest_flush_tlb_mask(d, d->dirty_cpumask);
-- return;
-+ return true;
- }
- }
- }
-@@ -987,7 +990,12 @@ static void _shadow_prealloc(struct doma
- d->arch.paging.shadow.total_pages,
- d->arch.paging.shadow.free_pages,
- d->arch.paging.shadow.p2m_pages);
-- BUG();
-+
-+ ASSERT(d->is_dying);
-+
-+ guest_flush_tlb_mask(d, d->dirty_cpumask);
-+
-+ return false;
- }
-
- /* Make sure there are at least count pages of the order according to
-@@ -995,9 +1003,19 @@ static void _shadow_prealloc(struct doma
- * This must be called before any calls to shadow_alloc(). Since this
- * will free existing shadows to make room, it must be called early enough
- * to avoid freeing shadows that the caller is currently working on. */
--void shadow_prealloc(struct domain *d, u32 type, unsigned int count)
-+bool shadow_prealloc(struct domain *d, unsigned int type, unsigned int count)
- {
-- return _shadow_prealloc(d, shadow_size(type) * count);
-+ bool ret = _shadow_prealloc(d, shadow_size(type) * count);
-+
-+ if ( !ret && !d->is_dying &&
-+ (!d->is_shutting_down || d->shutdown_code != SHUTDOWN_crash) )
-+ /*
-+ * Failing to allocate memory required for shadow usage can only result in
-+ * a domain crash, do it here rather that relying on every caller to do it.
-+ */
-+ domain_crash(d);
-+
-+ return ret;
- }
-
- /* Deliberately free all the memory we can: this will tear down all of
-@@ -1218,7 +1236,7 @@ void shadow_free(struct domain *d, mfn_t
- static struct page_info *
- shadow_alloc_p2m_page(struct domain *d)
- {
-- struct page_info *pg;
-+ struct page_info *pg = NULL;
-
- /* This is called both from the p2m code (which never holds the
- * paging lock) and the log-dirty code (which always does). */
-@@ -1236,16 +1254,18 @@ shadow_alloc_p2m_page(struct domain *d)
- d->arch.paging.shadow.p2m_pages,
- shadow_min_acceptable_pages(d));
- }
-- paging_unlock(d);
-- return NULL;
-+ goto out;
- }
-
-- shadow_prealloc(d, SH_type_p2m_table, 1);
-+ if ( !shadow_prealloc(d, SH_type_p2m_table, 1) )
-+ goto out;
-+
- pg = mfn_to_page(shadow_alloc(d, SH_type_p2m_table, 0));
- d->arch.paging.shadow.p2m_pages++;
- d->arch.paging.shadow.total_pages--;
- ASSERT(!page_get_owner(pg) && !(pg->count_info & PGC_count_mask));
-
-+ out:
- paging_unlock(d);
-
- return pg;
-@@ -1336,7 +1356,9 @@ int shadow_set_allocation(struct domain
- else if ( d->arch.paging.shadow.total_pages > pages )
- {
- /* Need to return memory to domheap */
-- _shadow_prealloc(d, 1);
-+ if ( !_shadow_prealloc(d, 1) )
-+ return -ENOMEM;
-+
- sp = page_list_remove_head(&d->arch.paging.shadow.freelist);
- ASSERT(sp);
- /*
-@@ -2334,12 +2356,13 @@ static void sh_update_paging_modes(struc
- if ( mfn_eq(v->arch.paging.shadow.oos_snapshot[0], INVALID_MFN) )
- {
- int i;
-+
-+ if ( !shadow_prealloc(d, SH_type_oos_snapshot, SHADOW_OOS_PAGES) )
-+ return;
-+
- for(i = 0; i < SHADOW_OOS_PAGES; i++)
-- {
-- shadow_prealloc(d, SH_type_oos_snapshot, 1);
- v->arch.paging.shadow.oos_snapshot[i] =
- shadow_alloc(d, SH_type_oos_snapshot, 0);
-- }
- }
- #endif /* OOS */
-
-@@ -2403,6 +2426,9 @@ static void sh_update_paging_modes(struc
- mfn_t mmfn = sh_make_monitor_table(
- v, v->arch.paging.mode->shadow.shadow_levels);
-
-+ if ( mfn_eq(mmfn, INVALID_MFN) )
-+ return;
-+
- v->arch.hvm.monitor_table = pagetable_from_mfn(mmfn);
- make_cr3(v, mmfn);
- hvm_update_host_cr3(v);
-@@ -2441,6 +2467,12 @@ static void sh_update_paging_modes(struc
- v->arch.hvm.monitor_table = pagetable_null();
- new_mfn = sh_make_monitor_table(
- v, v->arch.paging.mode->shadow.shadow_levels);
-+ if ( mfn_eq(new_mfn, INVALID_MFN) )
-+ {
-+ sh_destroy_monitor_table(v, old_mfn,
-+ old_mode->shadow.shadow_levels);
-+ return;
-+ }
- v->arch.hvm.monitor_table = pagetable_from_mfn(new_mfn);
- SHADOW_PRINTK("new monitor table %"PRI_mfn "\n",
- mfn_x(new_mfn));
-@@ -2526,7 +2558,12 @@ void sh_set_toplevel_shadow(struct vcpu
- if ( !mfn_valid(smfn) )
- {
- /* Make sure there's enough free shadow memory. */
-- shadow_prealloc(d, root_type, 1);
-+ if ( !shadow_prealloc(d, root_type, 1) )
-+ {
-+ new_entry = pagetable_null();
-+ goto install_new_entry;
-+ }
-+
- /* Shadow the page. */
- smfn = make_shadow(v, gmfn, root_type);
- }
---- a/xen/arch/x86/mm/shadow/hvm.c
-+++ b/xen/arch/x86/mm/shadow/hvm.c
-@@ -700,7 +700,9 @@ mfn_t sh_make_monitor_table(const struct
- ASSERT(!pagetable_get_pfn(v->arch.hvm.monitor_table));
-
- /* Guarantee we can get the memory we need */
-- shadow_prealloc(d, SH_type_monitor_table, CONFIG_PAGING_LEVELS);
-+ if ( !shadow_prealloc(d, SH_type_monitor_table, CONFIG_PAGING_LEVELS) )
-+ return INVALID_MFN;
-+
- m4mfn = shadow_alloc(d, SH_type_monitor_table, 0);
- mfn_to_page(m4mfn)->shadow_flags = 4;
-
---- a/xen/arch/x86/mm/shadow/multi.c
-+++ b/xen/arch/x86/mm/shadow/multi.c
-@@ -2440,9 +2440,14 @@ static int sh_page_fault(struct vcpu *v,
- * Preallocate shadow pages *before* removing writable accesses
- * otherwhise an OOS L1 might be demoted and promoted again with
- * writable mappings. */
-- shadow_prealloc(d,
-- SH_type_l1_shadow,
-- GUEST_PAGING_LEVELS < 4 ? 1 : GUEST_PAGING_LEVELS - 1);
-+ if ( !shadow_prealloc(d, SH_type_l1_shadow,
-+ GUEST_PAGING_LEVELS < 4
-+ ? 1 : GUEST_PAGING_LEVELS - 1) )
-+ {
-+ paging_unlock(d);
-+ put_gfn(d, gfn_x(gfn));
-+ return 0;
-+ }
-
- rc = gw_remove_write_accesses(v, va, &gw);
-
---- a/xen/arch/x86/mm/shadow/private.h
-+++ b/xen/arch/x86/mm/shadow/private.h
-@@ -383,7 +383,8 @@ void shadow_promote(struct domain *d, mf
- void shadow_demote(struct domain *d, mfn_t gmfn, u32 type);
-
- /* Shadow page allocation functions */
--void shadow_prealloc(struct domain *d, u32 shadow_type, unsigned int count);
-+bool __must_check shadow_prealloc(struct domain *d, unsigned int shadow_type,
-+ unsigned int count);
- mfn_t shadow_alloc(struct domain *d,
- u32 shadow_type,
- unsigned long backpointer);
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-27 02:15:30 +0000