aboutsummaryrefslogtreecommitdiffstats
path: root/main/xen/xsa201-2.patch
diff options
context:
space:
mode:
authorLeonardo Arena <rnalrd@alpinelinux.org>2017-10-25 13:39:25 +0000
committerLeonardo Arena <rnalrd@alpinelinux.org>2017-10-25 13:39:25 +0000
commitd19612e9b3adfc33b29c071630e17fd1a15f36cd (patch)
tree3918eb846783cc4844b4281bf3090485002693f5 /main/xen/xsa201-2.patch
parent44b88acb3ab4b4377a196dca03c7879cb443a3e0 (diff)
downloadaports-d19612e9b3adfc33b29c071630e17fd1a15f36cd.tar.bz2
aports-d19612e9b3adfc33b29c071630e17fd1a15f36cd.tar.xz
main/xen: security upgrade to 4.6.6
Diffstat (limited to 'main/xen/xsa201-2.patch')
-rw-r--r--main/xen/xsa201-2.patch199
1 files changed, 0 insertions, 199 deletions
diff --git a/main/xen/xsa201-2.patch b/main/xen/xsa201-2.patch
deleted file mode 100644
index 9bd1f8f89d..0000000000
--- a/main/xen/xsa201-2.patch
+++ /dev/null
@@ -1,199 +0,0 @@
-From: Wei Chen <Wei.Chen@arm.com>
-Subject: arm64: handle async aborts delivered while at EL2
-
-If EL1 generates an asynchronous abort and then traps into EL2
-(by HVC or IRQ) before the abort has been delivered, the hypervisor
-could not catch it, because the PSTATE.A bit is masked all the time
-in hypervisor. So this asynchronous abort may be slipped to next
-running guest with PSTATE.A bit unmasked.
-
-In order to avoid this, it is necessary to take the abort at EL2, by
-clearing the PSTATE.A bit. In this patch, we unmask the PSTATE.A bit
-to open a window to catch guest-generated asynchronous abort in all
-EL1 -> EL2 swich paths. If we catched such asynchronous abort in
-checking window, the hyp_error exception will be triggered and the
-abort source guest will be crashed.
-
-This is CVE-2016-9816, part of XSA-201.
-
-Signed-off-by: Wei Chen <Wei.Chen@arm.com>
-Reviewed-by: Julien Grall <julien.grall@arm.com>
-
---- a/xen/arch/arm/arm64/entry.S
-+++ b/xen/arch/arm/arm64/entry.S
-@@ -173,6 +173,43 @@ hyp_error_invalid:
- entry hyp=1
- invalid BAD_ERROR
-
-+hyp_error:
-+ /*
-+ * Only two possibilities:
-+ * 1) Either we come from the exit path, having just unmasked
-+ * PSTATE.A: change the return code to an EL2 fault, and
-+ * carry on, as we're already in a sane state to handle it.
-+ * 2) Or we come from anywhere else, and that's a bug: we panic.
-+ */
-+ entry hyp=1
-+ msr daifclr, #2
-+
-+ /*
-+ * The ELR_EL2 may be modified by an interrupt, so we have to use the
-+ * saved value in cpu_user_regs to check whether we come from 1) or
-+ * not.
-+ */
-+ ldr x0, [sp, #UREGS_PC]
-+ adr x1, abort_guest_exit_start
-+ cmp x0, x1
-+ adr x1, abort_guest_exit_end
-+ ccmp x0, x1, #4, ne
-+ mov x0, sp
-+ mov x1, #BAD_ERROR
-+
-+ /*
-+ * Not equal, the exception come from 2). It's a bug, we have to
-+ * panic the hypervisor.
-+ */
-+ b.ne do_bad_mode
-+
-+ /*
-+ * Otherwise, the exception come from 1). It happened because of
-+ * the guest. Crash this guest.
-+ */
-+ bl do_trap_guest_error
-+ exit hyp=1
-+
- /* Traps taken in Current EL with SP_ELx */
- hyp_sync:
- entry hyp=1
-@@ -189,15 +226,29 @@ hyp_irq:
-
- guest_sync:
- entry hyp=0, compat=0
-+ bl check_pending_vserror
-+ /*
-+ * If x0 is Non-zero, a vSError took place, the initial exception
-+ * doesn't have any significance to be handled. Exit ASAP
-+ */
-+ cbnz x0, 1f
- msr daifclr, #2
- mov x0, sp
- bl do_trap_hypervisor
-+1:
- exit hyp=0, compat=0
-
- guest_irq:
- entry hyp=0, compat=0
-+ bl check_pending_vserror
-+ /*
-+ * If x0 is Non-zero, a vSError took place, the initial exception
-+ * doesn't have any significance to be handled. Exit ASAP
-+ */
-+ cbnz x0, 1f
- mov x0, sp
- bl do_trap_irq
-+1:
- exit hyp=0, compat=0
-
- guest_fiq_invalid:
-@@ -213,15 +264,29 @@ guest_error:
-
- guest_sync_compat:
- entry hyp=0, compat=1
-+ bl check_pending_vserror
-+ /*
-+ * If x0 is Non-zero, a vSError took place, the initial exception
-+ * doesn't have any significance to be handled. Exit ASAP
-+ */
-+ cbnz x0, 1f
- msr daifclr, #2
- mov x0, sp
- bl do_trap_hypervisor
-+1:
- exit hyp=0, compat=1
-
- guest_irq_compat:
- entry hyp=0, compat=1
-+ bl check_pending_vserror
-+ /*
-+ * If x0 is Non-zero, a vSError took place, the initial exception
-+ * doesn't have any significance to be handled. Exit ASAP
-+ */
-+ cbnz x0, 1f
- mov x0, sp
- bl do_trap_irq
-+1:
- exit hyp=0, compat=1
-
- guest_fiq_invalid_compat:
-@@ -270,6 +335,62 @@ return_from_trap:
- eret
-
- /*
-+ * This function is used to check pending virtual SError in the gap of
-+ * EL1 -> EL2 world switch.
-+ * The x0 register will be used to indicate the results of detection.
-+ * x0 -- Non-zero indicates a pending virtual SError took place.
-+ * x0 -- Zero indicates no pending virtual SError took place.
-+ */
-+check_pending_vserror:
-+ /*
-+ * Save elr_el2 to check whether the pending SError exception takes
-+ * place while we are doing this sync exception.
-+ */
-+ mrs x0, elr_el2
-+
-+ /* Synchronize against in-flight ld/st */
-+ dsb sy
-+
-+ /*
-+ * Unmask PSTATE asynchronous abort bit. If there is a pending
-+ * SError, the EL2 error exception will happen after PSTATE.A
-+ * is cleared.
-+ */
-+ msr daifclr, #4
-+
-+ /*
-+ * This is our single instruction exception window. A pending
-+ * SError is guaranteed to occur at the earliest when we unmask
-+ * it, and at the latest just after the ISB.
-+ *
-+ * If a pending SError occurs, the program will jump to EL2 error
-+ * exception handler, and the elr_el2 will be set to
-+ * abort_guest_exit_start or abort_guest_exit_end.
-+ */
-+abort_guest_exit_start:
-+
-+ isb
-+
-+abort_guest_exit_end:
-+ /* Mask PSTATE asynchronous abort bit, close the checking window. */
-+ msr daifset, #4
-+
-+ /*
-+ * Compare elr_el2 and the saved value to check whether we are
-+ * returning from a valid exception caused by pending SError.
-+ */
-+ mrs x1, elr_el2
-+ cmp x0, x1
-+
-+ /*
-+ * Not equal, the pending SError exception took place, set
-+ * x0 to non-zero.
-+ */
-+ cset x0, ne
-+
-+ ret
-+
-+/*
- * Exception vectors.
- */
- .macro ventry label
-@@ -287,7 +408,7 @@ ENTRY(hyp_traps_vector)
- ventry hyp_sync // Synchronous EL2h
- ventry hyp_irq // IRQ EL2h
- ventry hyp_fiq_invalid // FIQ EL2h
-- ventry hyp_error_invalid // Error EL2h
-+ ventry hyp_error // Error EL2h
-
- ventry guest_sync // Synchronous 64-bit EL0/EL1
- ventry guest_irq // IRQ 64-bit EL0/EL1