s390: add ARCH_HAS_DEBUG_WX support
Checks the whole kernel address space for W+X mappings. Note that currently the first lowcore page unfortunately has to be mapped W+X. Therefore this not reported as an insecure mapping. For the very same reason the wording is also different to other architectures if the test passes: On s390 it is "no unexpected W+X pages found" instead of "no W+X pages found". Tested-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
This commit is contained in:
parent
6bf9a639e7
commit
08c8e685c7
|
@ -60,6 +60,7 @@ config S390
|
|||
def_bool y
|
||||
select ARCH_BINFMT_ELF_STATE
|
||||
select ARCH_HAS_DEBUG_VM_PGTABLE
|
||||
select ARCH_HAS_DEBUG_WX
|
||||
select ARCH_HAS_DEVMEM_IS_ALLOWED
|
||||
select ARCH_HAS_ELF_RANDOMIZE
|
||||
select ARCH_HAS_FORTIFY_SOURCE
|
||||
|
|
|
@ -774,6 +774,7 @@ CONFIG_MAGIC_SYSRQ=y
|
|||
CONFIG_DEBUG_PAGEALLOC=y
|
||||
CONFIG_PAGE_OWNER=y
|
||||
CONFIG_DEBUG_RODATA_TEST=y
|
||||
CONFIG_DEBUG_WX=y
|
||||
CONFIG_PTDUMP_DEBUGFS=y
|
||||
CONFIG_DEBUG_OBJECTS=y
|
||||
CONFIG_DEBUG_OBJECTS_SELFTEST=y
|
||||
|
|
|
@ -758,6 +758,7 @@ CONFIG_GDB_SCRIPTS=y
|
|||
CONFIG_FRAME_WARN=1024
|
||||
CONFIG_DEBUG_SECTION_MISMATCH=y
|
||||
CONFIG_MAGIC_SYSRQ=y
|
||||
CONFIG_DEBUG_WX=y
|
||||
CONFIG_PTDUMP_DEBUGFS=y
|
||||
CONFIG_DEBUG_MEMORY_INIT=y
|
||||
CONFIG_PANIC_ON_OOPS=y
|
||||
|
|
14
arch/s390/include/asm/ptdump.h
Normal file
14
arch/s390/include/asm/ptdump.h
Normal file
|
@ -0,0 +1,14 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0 */
|
||||
|
||||
#ifndef _ASM_S390_PTDUMP_H
|
||||
#define _ASM_S390_PTDUMP_H
|
||||
|
||||
void ptdump_check_wx(void);
|
||||
|
||||
static inline void debug_checkwx(void)
|
||||
{
|
||||
if (IS_ENABLED(CONFIG_DEBUG_WX))
|
||||
ptdump_check_wx();
|
||||
}
|
||||
|
||||
#endif /* _ASM_S390_PTDUMP_H */
|
|
@ -8,7 +8,7 @@ obj-y += page-states.o pageattr.o pgtable.o pgalloc.o
|
|||
|
||||
obj-$(CONFIG_CMM) += cmm.o
|
||||
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
|
||||
obj-$(CONFIG_PTDUMP_DEBUGFS) += dump_pagetables.o
|
||||
obj-$(CONFIG_PTDUMP_CORE) += dump_pagetables.o
|
||||
obj-$(CONFIG_PGSTE) += gmap.o
|
||||
|
||||
KASAN_SANITIZE_kasan_init.o := n
|
||||
|
|
|
@ -5,6 +5,7 @@
|
|||
#include <linux/debugfs.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/kasan.h>
|
||||
#include <asm/ptdump.h>
|
||||
#include <asm/kasan.h>
|
||||
#include <asm/sections.h>
|
||||
|
||||
|
@ -47,6 +48,8 @@ struct pg_state {
|
|||
struct seq_file *seq;
|
||||
int level;
|
||||
unsigned int current_prot;
|
||||
bool check_wx;
|
||||
unsigned long wx_pages;
|
||||
unsigned long start_address;
|
||||
const struct addr_marker *marker;
|
||||
};
|
||||
|
@ -81,6 +84,26 @@ static void print_prot(struct seq_file *m, unsigned int pr, int level)
|
|||
pt_dump_seq_puts(m, (pr & _PAGE_NOEXEC) ? "NX\n" : "X\n");
|
||||
}
|
||||
|
||||
static void note_prot_wx(struct pg_state *st, unsigned long addr)
|
||||
{
|
||||
#ifdef CONFIG_DEBUG_WX
|
||||
if (!st->check_wx)
|
||||
return;
|
||||
if (st->current_prot & _PAGE_INVALID)
|
||||
return;
|
||||
if (st->current_prot & _PAGE_PROTECT)
|
||||
return;
|
||||
if (st->current_prot & _PAGE_NOEXEC)
|
||||
return;
|
||||
/* The first lowcore page is currently still W+X. */
|
||||
if (addr == PAGE_SIZE)
|
||||
return;
|
||||
WARN_ONCE(1, "s390/mm: Found insecure W+X mapping at address %pS\n",
|
||||
(void *)st->start_address);
|
||||
st->wx_pages += (addr - st->start_address) / PAGE_SIZE;
|
||||
#endif /* CONFIG_DEBUG_WX */
|
||||
}
|
||||
|
||||
static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, u64 val)
|
||||
{
|
||||
int width = sizeof(unsigned long) * 2;
|
||||
|
@ -109,6 +132,7 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
|
|||
st->level = level;
|
||||
} else if (prot != st->current_prot || level != st->level ||
|
||||
addr >= st->marker[1].start_address) {
|
||||
note_prot_wx(st, addr);
|
||||
pt_dump_seq_printf(m, "0x%0*lx-0x%0*lx ",
|
||||
width, st->start_address,
|
||||
width, addr);
|
||||
|
@ -129,6 +153,40 @@ static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level,
|
|||
}
|
||||
}
|
||||
|
||||
#ifdef CONFIG_DEBUG_WX
|
||||
void ptdump_check_wx(void)
|
||||
{
|
||||
struct pg_state st = {
|
||||
.ptdump = {
|
||||
.note_page = note_page,
|
||||
.range = (struct ptdump_range[]) {
|
||||
{.start = 0, .end = max_addr},
|
||||
{.start = 0, .end = 0},
|
||||
}
|
||||
},
|
||||
.seq = NULL,
|
||||
.level = -1,
|
||||
.current_prot = 0,
|
||||
.check_wx = true,
|
||||
.wx_pages = 0,
|
||||
.start_address = 0,
|
||||
.marker = (struct addr_marker[]) {
|
||||
{ .start_address = 0, .name = NULL},
|
||||
{ .start_address = -1, .name = NULL},
|
||||
},
|
||||
};
|
||||
|
||||
if (!MACHINE_HAS_NX)
|
||||
return;
|
||||
ptdump_walk_pgd(&st.ptdump, &init_mm, NULL);
|
||||
if (st.wx_pages)
|
||||
pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n", st.wx_pages);
|
||||
else
|
||||
pr_info("Checked W+X mappings: passed, no unexpected W+X pages found\n");
|
||||
}
|
||||
#endif /* CONFIG_DEBUG_WX */
|
||||
|
||||
#ifdef CONFIG_PTDUMP_DEBUGFS
|
||||
static int ptdump_show(struct seq_file *m, void *v)
|
||||
{
|
||||
struct pg_state st = {
|
||||
|
@ -142,6 +200,8 @@ static int ptdump_show(struct seq_file *m, void *v)
|
|||
.seq = m,
|
||||
.level = -1,
|
||||
.current_prot = 0,
|
||||
.check_wx = false,
|
||||
.wx_pages = 0,
|
||||
.start_address = 0,
|
||||
.marker = address_markers,
|
||||
};
|
||||
|
@ -154,6 +214,7 @@ static int ptdump_show(struct seq_file *m, void *v)
|
|||
return 0;
|
||||
}
|
||||
DEFINE_SHOW_ATTRIBUTE(ptdump);
|
||||
#endif /* CONFIG_PTDUMP_DEBUGFS */
|
||||
|
||||
static int pt_dump_init(void)
|
||||
{
|
||||
|
@ -167,7 +228,8 @@ static int pt_dump_init(void)
|
|||
address_markers[MODULES_NR].start_address = MODULES_VADDR;
|
||||
address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap;
|
||||
address_markers[VMALLOC_NR].start_address = VMALLOC_START;
|
||||
debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops);
|
||||
if (IS_ENABLED(CONFIG_PTDUMP_DEBUGFS))
|
||||
debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops);
|
||||
return 0;
|
||||
}
|
||||
device_initcall(pt_dump_init);
|
||||
|
|
|
@ -34,6 +34,7 @@
|
|||
#include <asm/processor.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <asm/pgalloc.h>
|
||||
#include <asm/ptdump.h>
|
||||
#include <asm/dma.h>
|
||||
#include <asm/lowcore.h>
|
||||
#include <asm/tlb.h>
|
||||
|
@ -129,6 +130,7 @@ void mark_rodata_ro(void)
|
|||
|
||||
set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
|
||||
pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
|
||||
debug_checkwx();
|
||||
}
|
||||
|
||||
int set_memory_encrypted(unsigned long addr, int numpages)
|
||||
|
|
Loading…
Reference in a new issue