diff options
Diffstat (limited to '0044-x86-HAP-adjust-monitor-table-related-error-handling.patch')
| -rw-r--r-- | 0044-x86-HAP-adjust-monitor-table-related-error-handling.patch | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/0044-x86-HAP-adjust-monitor-table-related-error-handling.patch b/0044-x86-HAP-adjust-monitor-table-related-error-handling.patch new file mode 100644 index 0000000..39db626 --- /dev/null +++ b/0044-x86-HAP-adjust-monitor-table-related-error-handling.patch @@ -0,0 +1,77 @@ +From d24a10a91d46a56e1d406239643ec651a31033d4 Mon Sep 17 00:00:00 2001 +From: Jan Beulich <jbeulich@suse.com> +Date: Tue, 11 Oct 2022 15:07:42 +0200 +Subject: [PATCH 44/67] x86/HAP: adjust monitor table related error handling +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +hap_make_monitor_table() will return INVALID_MFN if it encounters an +error condition, but hap_update_paging_modes() wasn’t handling this +value, resulting in an inappropriate value being stored in +monitor_table. This would subsequently misguide at least +hap_vcpu_teardown(). Avoid this by bailing early. + +Further, when a domain has/was already crashed or (perhaps less +important as there's no such path known to lead here) is already dying, +avoid calling domain_crash() on it again - that's at best confusing. + +This is part of CVE-2022-33746 / XSA-410. + +Signed-off-by: Jan Beulich <jbeulich@suse.com> +Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> +master commit: 5b44a61180f4f2e4f490a28400c884dd357ff45d +master date: 2022-10-11 14:21:56 +0200 +--- + xen/arch/x86/mm/hap/hap.c | 14 ++++++++++++-- + 1 file changed, 12 insertions(+), 2 deletions(-) + +diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c +index a8f5a19da917..d75dc2b9ed3d 100644 +--- a/xen/arch/x86/mm/hap/hap.c ++++ b/xen/arch/x86/mm/hap/hap.c +@@ -39,6 +39,7 @@ + #include <asm/domain.h> + #include <xen/numa.h> + #include <asm/hvm/nestedhvm.h> ++#include <public/sched.h> + + #include "private.h" + +@@ -405,8 +406,13 @@ static mfn_t hap_make_monitor_table(struct vcpu *v) + return m4mfn; + + oom: +- printk(XENLOG_G_ERR "out of memory building monitor pagetable\n"); +- domain_crash(d); ++ if ( !d->is_dying && ++ (!d->is_shutting_down || d->shutdown_code != SHUTDOWN_crash) ) ++ { ++ printk(XENLOG_G_ERR "%pd: out of memory building monitor pagetable\n", ++ d); ++ domain_crash(d); ++ } + return INVALID_MFN; + } + +@@ -766,6 +772,9 @@ static void hap_update_paging_modes(struct vcpu *v) + if ( pagetable_is_null(v->arch.hvm.monitor_table) ) + { + mfn_t mmfn = hap_make_monitor_table(v); ++ ++ if ( mfn_eq(mmfn, INVALID_MFN) ) ++ goto unlock; + v->arch.hvm.monitor_table = pagetable_from_mfn(mmfn); + make_cr3(v, mmfn); + hvm_update_host_cr3(v); +@@ -774,6 +783,7 @@ static void hap_update_paging_modes(struct vcpu *v) + /* CR3 is effectively updated by a mode change. Flush ASIDs, etc. */ + hap_update_cr3(v, 0, false); + ++ unlock: + paging_unlock(d); + put_gfn(d, cr3_gfn); + } +-- +2.37.3 + |