diff options
| -rw-r--r-- | system/xen/dom0/README.dom0 | 2 | ||||
| -rw-r--r-- | system/xen/xen.SlackBuild | 2 | ||||
| -rw-r--r-- | system/xen/xsa/xsa246-4.9.patch | 74 | ||||
| -rw-r--r-- | system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch | 176 | ||||
| -rw-r--r-- | system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch | 109 | ||||
| -rw-r--r-- | system/xen/xsa/xsa248.patch | 164 | ||||
| -rw-r--r-- | system/xen/xsa/xsa249.patch | 42 | ||||
| -rw-r--r-- | system/xen/xsa/xsa250.patch | 67 | ||||
| -rw-r--r-- | system/xen/xsa/xsa251.patch | 21 |
9 files changed, 655 insertions, 2 deletions
diff --git a/system/xen/dom0/README.dom0 b/system/xen/dom0/README.dom0 index 2521cf48bc..d5a40ce67a 100644 --- a/system/xen/dom0/README.dom0 +++ b/system/xen/dom0/README.dom0 @@ -46,7 +46,7 @@ Xen EFI binary. To make things a bit easier, a copy of Xen EFI binary can be found here: - http://slackware.hr/~mario/xen/xen-4.9.0.efi.gz + http://slackware.hr/~mario/xen/xen-4.9.1.efi.gz If an automatic boot to Xen kernel is desired, the binary should be renamed and copied to the following location: /boot/efi/EFI/BOOT/bootx64.efi diff --git a/system/xen/xen.SlackBuild b/system/xen/xen.SlackBuild index 5eb6f10673..4214e973d1 100644 --- a/system/xen/xen.SlackBuild +++ b/system/xen/xen.SlackBuild @@ -24,7 +24,7 @@ PRGNAM=xen VERSION=${VERSION:-4.9.1} -BUILD=${BUILD:-1} +BUILD=${BUILD:-2} TAG=${TAG:-_SBo} SEABIOS=${SEABIOS:-1.10.0} diff --git a/system/xen/xsa/xsa246-4.9.patch b/system/xen/xsa/xsa246-4.9.patch new file mode 100644 index 0000000000..6370a10625 --- /dev/null +++ b/system/xen/xsa/xsa246-4.9.patch @@ -0,0 +1,74 @@ +From: Julien Grall <julien.grall@linaro.org> +Subject: x86/pod: prevent infinite loop when shattering large pages + +When populating pages, the PoD may need to split large ones using +p2m_set_entry and request the caller to retry (see ept_get_entry for +instance). + +p2m_set_entry may fail to shatter if it is not possible to allocate +memory for the new page table. However, the error is not propagated +resulting to the callers to retry infinitely the PoD. + +Prevent the infinite loop by return false when it is not possible to +shatter the large mapping. + +This is XSA-246. + +Signed-off-by: Julien Grall <julien.grall@linaro.org> +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: George Dunlap <george.dunlap@citrix.com> + +--- a/xen/arch/x86/mm/p2m-pod.c ++++ b/xen/arch/x86/mm/p2m-pod.c +@@ -1071,9 +1071,8 @@ p2m_pod_demand_populate(struct p2m_domai + * NOTE: In a fine-grained p2m locking scenario this operation + * may need to promote its locking from gfn->1g superpage + */ +- p2m_set_entry(p2m, gfn_aligned, INVALID_MFN, PAGE_ORDER_2M, +- p2m_populate_on_demand, p2m->default_access); +- return 0; ++ return p2m_set_entry(p2m, gfn_aligned, INVALID_MFN, PAGE_ORDER_2M, ++ p2m_populate_on_demand, p2m->default_access); + } + + /* Only reclaim if we're in actual need of more cache. */ +@@ -1104,8 +1103,12 @@ p2m_pod_demand_populate(struct p2m_domai + + gfn_aligned = (gfn >> order) << order; + +- p2m_set_entry(p2m, gfn_aligned, mfn, order, p2m_ram_rw, +- p2m->default_access); ++ if ( p2m_set_entry(p2m, gfn_aligned, mfn, order, p2m_ram_rw, ++ p2m->default_access) ) ++ { ++ p2m_pod_cache_add(p2m, p, order); ++ goto out_fail; ++ } + + for( i = 0; i < (1UL << order); i++ ) + { +@@ -1150,13 +1153,18 @@ remap_and_retry: + BUG_ON(order != PAGE_ORDER_2M); + pod_unlock(p2m); + +- /* Remap this 2-meg region in singleton chunks */ +- /* NOTE: In a p2m fine-grained lock scenario this might +- * need promoting the gfn lock from gfn->2M superpage */ ++ /* ++ * Remap this 2-meg region in singleton chunks. See the comment on the ++ * 1G page splitting path above for why a single call suffices. ++ * ++ * NOTE: In a p2m fine-grained lock scenario this might ++ * need promoting the gfn lock from gfn->2M superpage. ++ */ + gfn_aligned = (gfn>>order)<<order; +- for(i=0; i<(1<<order); i++) +- p2m_set_entry(p2m, gfn_aligned + i, INVALID_MFN, PAGE_ORDER_4K, +- p2m_populate_on_demand, p2m->default_access); ++ if ( p2m_set_entry(p2m, gfn_aligned, INVALID_MFN, PAGE_ORDER_4K, ++ p2m_populate_on_demand, p2m->default_access) ) ++ return -1; ++ + if ( tb_init_done ) + { + struct { diff --git a/system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch b/system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch new file mode 100644 index 0000000000..ad9524a304 --- /dev/null +++ b/system/xen/xsa/xsa247-4.9-0001-p2m-Always-check-to-see-if-removing-a-p2m-entry-actu.patch @@ -0,0 +1,176 @@ +From ad208b8b7e45fb2b7c572b86c61c26412609e82d Mon Sep 17 00:00:00 2001 +From: George Dunlap <george.dunlap@citrix.com> +Date: Fri, 10 Nov 2017 16:53:54 +0000 +Subject: [PATCH 1/2] p2m: Always check to see if removing a p2m entry actually + worked + +The PoD zero-check functions speculatively remove memory from the p2m, +then check to see if it's completely zeroed, before putting it in the +cache. + +Unfortunately, the p2m_set_entry() calls may fail if the underlying +pagetable structure needs to change and the domain has exhausted its +p2m memory pool: for instance, if we're removing a 2MiB region out of +a 1GiB entry (in the p2m_pod_zero_check_superpage() case), or a 4k +region out of a 2MiB or larger entry (in the p2m_pod_zero_check() +case); and the return value is not checked. + +The underlying mfn will then be added into the PoD cache, and at some +point mapped into another location in the p2m. If the guest +afterwards ballons out this memory, it will be freed to the hypervisor +and potentially reused by another domain, in spite of the fact that +the original domain still has writable mappings to it. + +There are several places where p2m_set_entry() shouldn't be able to +fail, as it is guaranteed to write an entry of the same order that +succeeded before. Add a backstop of crashing the domain just in case, +and an ASSERT_UNREACHABLE() to flag up the broken assumption on debug +builds. + +While we're here, use PAGE_ORDER_2M rather than a magic constant. + +This is part of XSA-247. + +Reported-by: George Dunlap <george.dunlap.com> +Signed-off-by: George Dunlap <george.dunlap@citrix.com> +Reviewed-by: Jan Beulich <jbeulich@suse.com> +--- +v4: +- Removed some training whitespace +v3: +- Reformat reset clause to be more compact +- Make sure to set map[i] = NULL when unmapping in case we need to bail +v2: +- Crash a domain if a p2m_set_entry we think cannot fail fails anyway. +--- + xen/arch/x86/mm/p2m-pod.c | 77 +++++++++++++++++++++++++++++++++++++---------- + 1 file changed, 61 insertions(+), 16 deletions(-) + +diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c +index 730a48f928..f2ed751892 100644 +--- a/xen/arch/x86/mm/p2m-pod.c ++++ b/xen/arch/x86/mm/p2m-pod.c +@@ -752,8 +752,10 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) + } + + /* Try to remove the page, restoring old mapping if it fails. */ +- p2m_set_entry(p2m, gfn, INVALID_MFN, PAGE_ORDER_2M, +- p2m_populate_on_demand, p2m->default_access); ++ if ( p2m_set_entry(p2m, gfn, INVALID_MFN, PAGE_ORDER_2M, ++ p2m_populate_on_demand, p2m->default_access) ) ++ goto out; ++ + p2m_tlb_flush_sync(p2m); + + /* Make none of the MFNs are used elsewhere... for example, mapped +@@ -810,9 +812,18 @@ p2m_pod_zero_check_superpage(struct p2m_domain *p2m, unsigned long gfn) + ret = SUPERPAGE_PAGES; + + out_reset: +- if ( reset ) +- p2m_set_entry(p2m, gfn, mfn0, 9, type0, p2m->default_access); +- ++ /* ++ * This p2m_set_entry() call shouldn't be able to fail, since the same order ++ * on the same gfn succeeded above. If that turns out to be false, crashing ++ * the domain should be the safest way of making sure we don't leak memory. ++ */ ++ if ( reset && p2m_set_entry(p2m, gfn, mfn0, PAGE_ORDER_2M, ++ type0, p2m->default_access) ) ++ { ++ ASSERT_UNREACHABLE(); ++ domain_crash(d); ++ } ++ + out: + gfn_unlock(p2m, gfn, SUPERPAGE_ORDER); + return ret; +@@ -869,19 +880,30 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) + } + + /* Try to remove the page, restoring old mapping if it fails. */ +- p2m_set_entry(p2m, gfns[i], INVALID_MFN, PAGE_ORDER_4K, +- p2m_populate_on_demand, p2m->default_access); ++ if ( p2m_set_entry(p2m, gfns[i], INVALID_MFN, PAGE_ORDER_4K, ++ p2m_populate_on_demand, p2m->default_access) ) ++ goto skip; + + /* See if the page was successfully unmapped. (Allow one refcount + * for being allocated to a domain.) */ + if ( (mfn_to_page(mfns[i])->count_info & PGC_count_mask) > 1 ) + { ++ /* ++ * If the previous p2m_set_entry call succeeded, this one shouldn't ++ * be able to fail. If it does, crashing the domain should be safe. ++ */ ++ if ( p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K, ++ types[i], p2m->default_access) ) ++ { ++ ASSERT_UNREACHABLE(); ++ domain_crash(d); ++ goto out_unmap; ++ } ++ ++ skip: + unmap_domain_page(map[i]); + map[i] = NULL; + +- p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K, +- types[i], p2m->default_access); +- + continue; + } + } +@@ -900,12 +922,25 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) + + unmap_domain_page(map[i]); + +- /* See comment in p2m_pod_zero_check_superpage() re gnttab +- * check timing. */ +- if ( j < PAGE_SIZE/sizeof(*map[i]) ) ++ map[i] = NULL; ++ ++ /* ++ * See comment in p2m_pod_zero_check_superpage() re gnttab ++ * check timing. ++ */ ++ if ( j < (PAGE_SIZE / sizeof(*map[i])) ) + { +- p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K, +- types[i], p2m->default_access); ++ /* ++ * If the previous p2m_set_entry call succeeded, this one shouldn't ++ * be able to fail. If it does, crashing the domain should be safe. ++ */ ++ if ( p2m_set_entry(p2m, gfns[i], mfns[i], PAGE_ORDER_4K, ++ types[i], p2m->default_access) ) ++ { ++ ASSERT_UNREACHABLE(); ++ domain_crash(d); ++ goto out_unmap; ++ } + } + else + { +@@ -929,7 +964,17 @@ p2m_pod_zero_check(struct p2m_domain *p2m, unsigned long *gfns, int count) + p2m->pod.entry_count++; + } + } +- ++ ++ return; ++ ++out_unmap: ++ /* ++ * Something went wrong, probably crashing the domain. Unmap ++ * everything and return. ++ */ ++ for ( i = 0; i < count; i++ ) ++ if ( map[i] ) ++ unmap_domain_page(map[i]); + } + + #define POD_SWEEP_LIMIT 1024 +-- +2.15.0 + diff --git a/system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch b/system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch new file mode 100644 index 0000000000..8c850bd7f5 --- /dev/null +++ b/system/xen/xsa/xsa247-4.9-0002-p2m-Check-return-value-of-p2m_set_entry-when-decreas.patch @@ -0,0 +1,109 @@ +From d4bc7833707351a5341a6bdf04c752a028d9560d Mon Sep 17 00:00:00 2001 +From: George Dunlap <george.dunlap@citrix.com> +Date: Fri, 10 Nov 2017 16:53:55 +0000 +Subject: [PATCH 2/2] p2m: Check return value of p2m_set_entry() when + decreasing reservation + +If the entire range specified to p2m_pod_decrease_reservation() is marked +populate-on-demand, then it will make a single p2m_set_entry() call, +reducing its PoD entry count. + +Unfortunately, in the right circumstances, this p2m_set_entry() call +may fail. It that case, repeated calls to decrease_reservation() may +cause p2m->pod.entry_count to fall below zero, potentially tripping +over BUG_ON()s to the contrary. + +Instead, check to see if the entry succeeded, and return false if not. +The caller will then call guest_remove_page() on the gfns, which will +return -EINVAL upon finding no valid memory there to return. + +Unfortunately if the order > 0, the entry may have partially changed. +A domain_crash() is probably the safest thing in that case. + +Other p2m_set_entry() calls in the same function should be fine, +because they are writing the entry at its current order. Nonetheless, +check the return value and crash if our assumption turns otu to be +wrong. + +This is part of XSA-247. + +Reported-by: George Dunlap <george.dunlap.com> +Signed-off-by: George Dunlap <george.dunlap@citrix.com> +Reviewed-by: Jan Beulich <jbeulich@suse.com> +--- +v2: Crash the domain if we're not sure it's safe (or if we think it +can't happen) +--- + xen/arch/x86/mm/p2m-pod.c | 42 +++++++++++++++++++++++++++++++++--------- + 1 file changed, 33 insertions(+), 9 deletions(-) + +diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c +index f2ed751892..473d6a6dbf 100644 +--- a/xen/arch/x86/mm/p2m-pod.c ++++ b/xen/arch/x86/mm/p2m-pod.c +@@ -555,11 +555,23 @@ p2m_pod_decrease_reservation(struct domain *d, + + if ( !nonpod ) + { +- /* All PoD: Mark the whole region invalid and tell caller +- * we're done. */ +- p2m_set_entry(p2m, gpfn, INVALID_MFN, order, p2m_invalid, +- p2m->default_access); +- p2m->pod.entry_count-=(1<<order); ++ /* ++ * All PoD: Mark the whole region invalid and tell caller ++ * we're done. ++ */ ++ if ( p2m_set_entry(p2m, gpfn, INVALID_MFN, order, p2m_invalid, ++ p2m->default_access) ) ++ { ++ /* ++ * If this fails, we can't tell how much of the range was changed. ++ * Best to crash the domain unless we're sure a partial change is ++ * impossible. ++ */ ++ if ( order != 0 ) ++ domain_crash(d); ++ goto out_unlock; ++ } ++ p2m->pod.entry_count -= 1UL << order; + BUG_ON(p2m->pod.entry_count < 0); + ret = 1; + goto out_entry_check; +@@ -600,8 +612,14 @@ p2m_pod_decrease_reservation(struct domain *d, + n = 1UL << cur_order; + if ( t == p2m_populate_on_demand ) + { +- p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order, +- p2m_invalid, p2m->default_access); ++ /* This shouldn't be able to fail */ ++ if ( p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order, ++ p2m_invalid, p2m->default_access) ) ++ { ++ ASSERT_UNREACHABLE(); ++ domain_crash(d); ++ goto out_unlock; ++ } + p2m->pod.entry_count -= n; + BUG_ON(p2m->pod.entry_count < 0); + pod -= n; +@@ -622,8 +640,14 @@ p2m_pod_decrease_reservation(struct domain *d, + + page = mfn_to_page(mfn); + +- p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order, +- p2m_invalid, p2m->default_access); ++ /* This shouldn't be able to fail */ ++ if ( p2m_set_entry(p2m, gpfn + i, INVALID_MFN, cur_order, ++ p2m_invalid, p2m->default_access) ) ++ { ++ ASSERT_UNREACHABLE(); ++ domain_crash(d); ++ goto out_unlock; ++ } + p2m_tlb_flush_sync(p2m); + for ( j = 0; j < n; ++j ) + set_gpfn_from_mfn(mfn_x(mfn), INVALID_M2P_ENTRY); +-- +2.15.0 + diff --git a/system/xen/xsa/xsa248.patch b/system/xen/xsa/xsa248.patch new file mode 100644 index 0000000000..966c16e043 --- /dev/null +++ b/system/xen/xsa/xsa248.patch @@ -0,0 +1,164 @@ +From: Jan Beulich <jbeulich@suse.com> +Subject: x86/mm: don't wrongly set page ownership + +PV domains can obtain mappings of any pages owned by the correct domain, +including ones that aren't actually assigned as "normal" RAM, but used +by Xen internally. At the moment such "internal" pages marked as owned +by a guest include pages used to track logdirty bits, as well as p2m +pages and the "unpaged pagetable" for HVM guests. Since the PV memory +management and shadow code conflict in their use of struct page_info +fields, and since shadow code is being used for log-dirty handling for +PV domains, pages coming from the shadow pool must, for PV domains, not +have the domain set as their owner. + +While the change could be done conditionally for just the PV case in +shadow code, do it unconditionally (and for consistency also for HAP), +just to be on the safe side. + +There's one special case though for shadow code: The page table used for +running a HVM guest in unpaged mode is subject to get_page() (in +set_shadow_status()) and hence must have its owner set. + +This is XSA-248. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Tim Deegan <tim@xen.org> +Reviewed-by: George Dunlap <george.dunlap@citrix.com> +--- +v2: Drop PGC_page_table related pieces. + +--- a/xen/arch/x86/mm/hap/hap.c ++++ b/xen/arch/x86/mm/hap/hap.c +@@ -286,8 +286,7 @@ static struct page_info *hap_alloc_p2m_p + { + d->arch.paging.hap.total_pages--; + d->arch.paging.hap.p2m_pages++; +- page_set_owner(pg, d); +- pg->count_info |= 1; ++ ASSERT(!page_get_owner(pg) && !(pg->count_info & PGC_count_mask)); + } + else if ( !d->arch.paging.p2m_alloc_failed ) + { +@@ -302,21 +301,23 @@ static struct page_info *hap_alloc_p2m_p + + static void hap_free_p2m_page(struct domain *d, struct page_info *pg) + { ++ struct domain *owner = page_get_owner(pg); ++ + /* This is called both from the p2m code (which never holds the + * paging lock) and the log-dirty code (which always does). */ + paging_lock_recursive(d); + +- ASSERT(page_get_owner(pg) == d); +- /* Should have just the one ref we gave it in alloc_p2m_page() */ +- if ( (pg->count_info & PGC_count_mask) != 1 ) { +- HAP_ERROR("Odd p2m page %p count c=%#lx t=%"PRtype_info"\n", +- pg, pg->count_info, pg->u.inuse.type_info); ++ /* Should still have no owner and count zero. */ ++ if ( owner || (pg->count_info & PGC_count_mask) ) ++ { ++ HAP_ERROR("d%d: Odd p2m page %"PRI_mfn" d=%d c=%lx t=%"PRtype_info"\n", ++ d->domain_id, mfn_x(page_to_mfn(pg)), ++ owner ? owner->domain_id : DOMID_INVALID, ++ pg->count_info, pg->u.inuse.type_info); + WARN(); ++ pg->count_info &= ~PGC_count_mask; ++ page_set_owner(pg, NULL); + } +- pg->count_info &= ~PGC_count_mask; +- /* Free should not decrement domain's total allocation, since +- * these pages were allocated without an owner. */ +- page_set_owner(pg, NULL); + d->arch.paging.hap.p2m_pages--; + d->arch.paging.hap.total_pages++; + hap_free(d, page_to_mfn(pg)); +--- a/xen/arch/x86/mm/shadow/common.c ++++ b/xen/arch/x86/mm/shadow/common.c +@@ -1503,32 +1503,29 @@ shadow_alloc_p2m_page(struct domain *d) + 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)); + + paging_unlock(d); + +- /* Unlike shadow pages, mark p2m pages as owned by the domain. +- * Marking the domain as the owner would normally allow the guest to +- * create mappings of these pages, but these p2m pages will never be +- * in the domain's guest-physical address space, and so that is not +- * believed to be a concern. */ +- page_set_owner(pg, d); +- pg->count_info |= 1; + return pg; + } + + static void + shadow_free_p2m_page(struct domain *d, struct page_info *pg) + { +- ASSERT(page_get_owner(pg) == d); +- /* Should have just the one ref we gave it in alloc_p2m_page() */ +- if ( (pg->count_info & PGC_count_mask) != 1 ) ++ struct domain *owner = page_get_owner(pg); ++ ++ /* Should still have no owner and count zero. */ ++ if ( owner || (pg->count_info & PGC_count_mask) ) + { +- SHADOW_ERROR("Odd p2m page count c=%#lx t=%"PRtype_info"\n", ++ SHADOW_ERROR("d%d: Odd p2m page %"PRI_mfn" d=%d c=%lx t=%"PRtype_info"\n", ++ d->domain_id, mfn_x(page_to_mfn(pg)), ++ owner ? owner->domain_id : DOMID_INVALID, + pg->count_info, pg->u.inuse.type_info); ++ pg->count_info &= ~PGC_count_mask; ++ page_set_owner(pg, NULL); + } +- pg->count_info &= ~PGC_count_mask; + pg->u.sh.type = SH_type_p2m_table; /* p2m code reuses type-info */ +- page_set_owner(pg, NULL); + + /* This is called both from the p2m code (which never holds the + * paging lock) and the log-dirty code (which always does). */ +@@ -3132,7 +3129,9 @@ int shadow_enable(struct domain *d, u32 + e = __map_domain_page(pg); + write_32bit_pse_identmap(e); + unmap_domain_page(e); ++ pg->count_info = 1; + pg->u.inuse.type_info = PGT_l2_page_table | 1 | PGT_validated; ++ page_set_owner(pg, d); + } + + paging_lock(d); +@@ -3170,7 +3169,11 @@ int shadow_enable(struct domain *d, u32 + if ( rv != 0 && !pagetable_is_null(p2m_get_pagetable(p2m)) ) + p2m_teardown(p2m); + if ( rv != 0 && pg != NULL ) ++ { ++ pg->count_info &= ~PGC_count_mask; ++ page_set_owner(pg, NULL); + shadow_free_p2m_page(d, pg); ++ } + domain_unpause(d); + return rv; + } +@@ -3279,7 +3282,22 @@ out: + + /* Must be called outside the lock */ + if ( unpaged_pagetable ) ++ { ++ if ( page_get_owner(unpaged_pagetable) == d && ++ (unpaged_pagetable->count_info & PGC_count_mask) == 1 ) ++ { ++ unpaged_pagetable->count_info &= ~PGC_count_mask; ++ page_set_owner(unpaged_pagetable, NULL); ++ } ++ /* Complain here in cases where shadow_free_p2m_page() won't. */ ++ else if ( !page_get_owner(unpaged_pagetable) && ++ !(unpaged_pagetable->count_info & PGC_count_mask) ) ++ SHADOW_ERROR("d%d: Odd unpaged pt %"PRI_mfn" c=%lx t=%"PRtype_info"\n", ++ d->domain_id, mfn_x(page_to_mfn(unpaged_pagetable)), ++ unpaged_pagetable->count_info, ++ unpaged_pagetable->u.inuse.type_info); + shadow_free_p2m_page(d, unpaged_pagetable); ++ } + } + + void shadow_final_teardown(struct domain *d) diff --git a/system/xen/xsa/xsa249.patch b/system/xen/xsa/xsa249.patch new file mode 100644 index 0000000000..ecfa4305e5 --- /dev/null +++ b/system/xen/xsa/xsa249.patch @@ -0,0 +1,42 @@ +From: Jan Beulich <jbeulich@suse.com> +Subject: x86/shadow: fix refcount overflow check + +Commit c385d27079 ("x86 shadow: for multi-page shadows, explicitly track +the first page") reduced the refcount width to 25, without adjusting the +overflow check. Eliminate the disconnect by using a manifest constant. + +Interestingly, up to commit 047782fa01 ("Out-of-sync L1 shadows: OOS +snapshot") the refcount was 27 bits wide, yet the check was already +using 26. + +This is XSA-249. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: George Dunlap <george.dunlap@citrix.com> +Reviewed-by: Tim Deegan <tim@xen.org> +--- +v2: Simplify expression back to the style it was. + +--- a/xen/arch/x86/mm/shadow/private.h ++++ b/xen/arch/x86/mm/shadow/private.h +@@ -529,7 +529,7 @@ static inline int sh_get_ref(struct doma + x = sp->u.sh.count; + nx = x + 1; + +- if ( unlikely(nx >= 1U<<26) ) ++ if ( unlikely(nx >= (1U << PAGE_SH_REFCOUNT_WIDTH)) ) + { + SHADOW_PRINTK("shadow ref overflow, gmfn=%lx smfn=%lx\n", + __backpointer(sp), mfn_x(smfn)); +--- a/xen/include/asm-x86/mm.h ++++ b/xen/include/asm-x86/mm.h +@@ -82,7 +82,8 @@ struct page_info + unsigned long type:5; /* What kind of shadow is this? */ + unsigned long pinned:1; /* Is the shadow pinned? */ + unsigned long head:1; /* Is this the first page of the shadow? */ +- unsigned long count:25; /* Reference count */ ++#define PAGE_SH_REFCOUNT_WIDTH 25 ++ unsigned long count:PAGE_SH_REFCOUNT_WIDTH; /* Reference count */ + } sh; + + /* Page is on a free list: ((count_info & PGC_count_mask) == 0). */ diff --git a/system/xen/xsa/xsa250.patch b/system/xen/xsa/xsa250.patch new file mode 100644 index 0000000000..26aeb33fed --- /dev/null +++ b/system/xen/xsa/xsa250.patch @@ -0,0 +1,67 @@ +From: Jan Beulich <jbeulich@suse.com> +Subject: x86/shadow: fix ref-counting error handling + +The old-Linux handling in shadow_set_l4e() mistakenly ORed together the +results of sh_get_ref() and sh_pin(). As the latter failing is not a +correctness problem, simply ignore its return value. + +In sh_set_toplevel_shadow() a failing sh_get_ref() must not be +accompanied by installing the entry, despite the domain being crashed. + +This is XSA-250. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Tim Deegan <tim@xen.org> + +--- a/xen/arch/x86/mm/shadow/multi.c ++++ b/xen/arch/x86/mm/shadow/multi.c +@@ -923,7 +923,7 @@ static int shadow_set_l4e(struct domain + shadow_l4e_t new_sl4e, + mfn_t sl4mfn) + { +- int flags = 0, ok; ++ int flags = 0; + shadow_l4e_t old_sl4e; + paddr_t paddr; + ASSERT(sl4e != NULL); +@@ -938,15 +938,16 @@ static int shadow_set_l4e(struct domain + { + /* About to install a new reference */ + mfn_t sl3mfn = shadow_l4e_get_mfn(new_sl4e); +- ok = sh_get_ref(d, sl3mfn, paddr); +- /* Are we pinning l3 shadows to handle wierd linux behaviour? */ +- if ( sh_type_is_pinnable(d, SH_type_l3_64_shadow) ) +- ok |= sh_pin(d, sl3mfn); +- if ( !ok ) ++ ++ if ( !sh_get_ref(d, sl3mfn, paddr) ) + { + domain_crash(d); + return SHADOW_SET_ERROR; + } ++ ++ /* Are we pinning l3 shadows to handle weird Linux behaviour? */ ++ if ( sh_type_is_pinnable(d, SH_type_l3_64_shadow) ) ++ sh_pin(d, sl3mfn); + } + + /* Write the new entry */ +@@ -3965,14 +3966,15 @@ sh_set_toplevel_shadow(struct vcpu *v, + + /* Take a ref to this page: it will be released in sh_detach_old_tables() + * or the next call to set_toplevel_shadow() */ +- if ( !sh_get_ref(d, smfn, 0) ) ++ if ( sh_get_ref(d, smfn, 0) ) ++ new_entry = pagetable_from_mfn(smfn); ++ else + { + SHADOW_ERROR("can't install %#lx as toplevel shadow\n", mfn_x(smfn)); + domain_crash(d); ++ new_entry = pagetable_null(); + } + +- new_entry = pagetable_from_mfn(smfn); +- + install_new_entry: + /* Done. Install it */ + SHADOW_PRINTK("%u/%u [%u] gmfn %#"PRI_mfn" smfn %#"PRI_mfn"\n", diff --git a/system/xen/xsa/xsa251.patch b/system/xen/xsa/xsa251.patch new file mode 100644 index 0000000000..582ef622eb --- /dev/null +++ b/system/xen/xsa/xsa251.patch @@ -0,0 +1,21 @@ +From: Jan Beulich <jbeulich@suse.com> +Subject: x86/paging: don't unconditionally BUG() on finding SHARED_M2P_ENTRY + +PV guests can fully control the values written into the P2M. + +This is XSA-251. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> + +--- a/xen/arch/x86/mm/paging.c ++++ b/xen/arch/x86/mm/paging.c +@@ -274,7 +274,7 @@ void paging_mark_pfn_dirty(struct domain + return; + + /* Shared MFNs should NEVER be marked dirty */ +- BUG_ON(SHARED_M2P(pfn_x(pfn))); ++ BUG_ON(paging_mode_translate(d) && SHARED_M2P(pfn_x(pfn))); + + /* + * Values with the MSB set denote MFNs that aren't really part of the |