From 5d180439d07774c5a2477cf9901c9b51c9edd74b Mon Sep 17 00:00:00 2001 From: Thomas Huth Date: Thu, 12 Feb 2015 18:09:21 +0100 Subject: [PATCH] s390x/mmu: Check table length and offset fields The ACSEs have a table length field and the region entries have table length and offset fields which must be checked during translation to see whether the given virtual address is really covered by the translation table. Signed-off-by: Thomas Huth Signed-off-by: Jens Freimann Signed-off-by: Christian Borntraeger --- target-s390x/cpu.h | 1 + target-s390x/mmu_helper.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h index 95d0f3b601..556304241a 100644 --- a/target-s390x/cpu.h +++ b/target-s390x/cpu.h @@ -837,6 +837,7 @@ struct sysib_322 { #define _ASCE_TABLE_LENGTH 0x03 /* region table length */ #define _REGION_ENTRY_ORIGIN ~0xfffULL /* region/segment table origin */ +#define _REGION_ENTRY_TF 0xc0 /* region/segment table offset */ #define _REGION_ENTRY_INV 0x20 /* invalid region table entry */ #define _REGION_ENTRY_TYPE_MASK 0x0c /* region/segment table type mask */ #define _REGION_ENTRY_TYPE_R1 0x0c /* region first table type */ diff --git a/target-s390x/mmu_helper.c b/target-s390x/mmu_helper.c index 01d819e026..d4087ba3ce 100644 --- a/target-s390x/mmu_helper.c +++ b/target-s390x/mmu_helper.c @@ -171,6 +171,10 @@ static int mmu_translate_region(CPUS390XState *env, target_ulong vaddr, { CPUState *cs = CPU(s390_env_get_cpu(env)); uint64_t origin, offs, new_entry; + const int pchks[4] = { + PGM_SEGMENT_TRANS, PGM_REG_THIRD_TRANS, + PGM_REG_SEC_TRANS, PGM_REG_FIRST_TRANS + }; PTE_DPRINTF("%s: 0x%" PRIx64 "\n", __func__, entry); @@ -201,6 +205,15 @@ static int mmu_translate_region(CPUS390XState *env, target_ulong vaddr, rw); } + /* Check region table offset and length */ + offs = (vaddr >> (28 + 11 * (level - 4) / 4)) & 3; + if (offs < ((new_entry & _REGION_ENTRY_TF) >> 6) + || offs > (new_entry & _REGION_ENTRY_LENGTH)) { + DPRINTF("%s: invalid offset or len (%lx)\n", __func__, new_entry); + trigger_page_fault(env, vaddr, pchks[level / 4 - 1], asc, rw); + return -1; + } + /* yet another region */ return mmu_translate_region(env, vaddr, asc, new_entry, level - 4, raddr, flags, rw); @@ -238,6 +251,10 @@ static int mmu_translate_asc(CPUS390XState *env, target_ulong vaddr, level = asce & _ASCE_TYPE_MASK; switch (level) { case _ASCE_TYPE_REGION1: + if ((vaddr >> 62) > (asce & _ASCE_TABLE_LENGTH)) { + trigger_page_fault(env, vaddr, PGM_REG_FIRST_TRANS, asc, rw); + return -1; + } break; case _ASCE_TYPE_REGION2: if (vaddr & 0xffe0000000000000ULL) { @@ -246,6 +263,10 @@ static int mmu_translate_asc(CPUS390XState *env, target_ulong vaddr, trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw); return -1; } + if ((vaddr >> 51 & 3) > (asce & _ASCE_TABLE_LENGTH)) { + trigger_page_fault(env, vaddr, PGM_REG_SEC_TRANS, asc, rw); + return -1; + } break; case _ASCE_TYPE_REGION3: if (vaddr & 0xfffffc0000000000ULL) { @@ -254,6 +275,10 @@ static int mmu_translate_asc(CPUS390XState *env, target_ulong vaddr, trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw); return -1; } + if ((vaddr >> 40 & 3) > (asce & _ASCE_TABLE_LENGTH)) { + trigger_page_fault(env, vaddr, PGM_REG_THIRD_TRANS, asc, rw); + return -1; + } break; case _ASCE_TYPE_SEGMENT: if (vaddr & 0xffffffff80000000ULL) { @@ -262,6 +287,10 @@ static int mmu_translate_asc(CPUS390XState *env, target_ulong vaddr, trigger_page_fault(env, vaddr, PGM_TRANS_SPEC, asc, rw); return -1; } + if ((vaddr >> 29 & 3) > (asce & _ASCE_TABLE_LENGTH)) { + trigger_page_fault(env, vaddr, PGM_SEGMENT_TRANS, asc, rw); + return -1; + } break; }