A set of EFI fixes:

- Enforce NX on RO data in mixed EFI mode
  - Destroy workqueue in an error handling path to prevent UAF
  - Stop argument parser at '--' which is the delimiter for init
  - Treat a NULL command line pointer as empty instead of dereferncing it
    unconditionally.
  - Handle an unterminated command line correctly
  - Cleanup the 32bit code leftovers and remove obsolete documentation
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Merge tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Thomas Gleixner:

 - Enforce NX on RO data in mixed EFI mode

 - Destroy workqueue in an error handling path to prevent UAF

 - Stop argument parser at '--' which is the delimiter for init

 - Treat a NULL command line pointer as empty instead of dereferncing it
   unconditionally.

 - Handle an unterminated command line correctly

 - Cleanup the 32bit code leftovers and remove obsolete documentation

* tag 'efi-urgent-2020-08-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation: efi: remove description of efi=old_map
  efi/x86: Move 32-bit code into efi_32.c
  efi/libstub: Handle unterminated cmdline
  efi/libstub: Handle NULL cmdline
  efi/libstub: Stop parsing arguments at "--"
  efi: add missed destroy_workqueue when efisubsys_init fails
  efi/x86: Mark kernel rodata non-executable for mixed mode
This commit is contained in:
Linus Torvalds 2020-08-23 11:08:32 -07:00
commit 10c091b62e
7 changed files with 52 additions and 92 deletions

View File

@ -1233,8 +1233,7 @@
efi= [EFI]
Format: { "debug", "disable_early_pci_dma",
"nochunk", "noruntime", "nosoftreserve",
"novamap", "no_disable_early_pci_dma",
"old_map" }
"novamap", "no_disable_early_pci_dma" }
debug: enable misc debug output.
disable_early_pci_dma: disable the busmaster bit on all
PCI bridges while in the EFI boot stub.
@ -1251,8 +1250,6 @@
novamap: do not call SetVirtualAddressMap().
no_disable_early_pci_dma: Leave the busmaster bit set
on all PCI bridges while in the EFI boot stub
old_map [X86-64]: switch to the old ioremap-based EFI
runtime services mapping. [Needs CONFIG_X86_UV=y]
efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of

View File

@ -81,11 +81,8 @@ extern unsigned long efi_fw_vendor, efi_config_table;
kernel_fpu_end(); \
})
#define arch_efi_call_virt(p, f, args...) p->f(args)
#define efi_ioremap(addr, size, type, attr) ioremap_cache(addr, size)
#else /* !CONFIG_X86_32 */
#define EFI_LOADER_SIGNATURE "EL64"
@ -125,9 +122,6 @@ struct efi_scratch {
kernel_fpu_end(); \
})
extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
u32 type, u64 attribute);
#ifdef CONFIG_KASAN
/*
* CONFIG_KASAN may redefine memset to __memset. __memset function is present
@ -143,17 +137,13 @@ extern void __iomem *__init efi_ioremap(unsigned long addr, unsigned long size,
#endif /* CONFIG_X86_32 */
extern struct efi_scratch efi_scratch;
extern void __init efi_set_executable(efi_memory_desc_t *md, bool executable);
extern int __init efi_memblock_x86_reserve_range(void);
extern void __init efi_print_memmap(void);
extern void __init efi_memory_uc(u64 addr, unsigned long size);
extern void __init efi_map_region(efi_memory_desc_t *md);
extern void __init efi_map_region_fixed(efi_memory_desc_t *md);
extern void efi_sync_low_kernel_mappings(void);
extern int __init efi_alloc_page_tables(void);
extern int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages);
extern void __init old_map_region(efi_memory_desc_t *md);
extern void __init runtime_code_page_mkexec(void);
extern void __init efi_runtime_update_mappings(void);
extern void __init efi_dump_pagetable(void);
extern void __init efi_apply_memmap_quirks(void);

View File

@ -49,7 +49,6 @@
#include <asm/efi.h>
#include <asm/e820/api.h>
#include <asm/time.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
#include <asm/x86_init.h>
#include <asm/uv/uv.h>
@ -496,74 +495,6 @@ void __init efi_init(void)
efi_print_memmap();
}
#if defined(CONFIG_X86_32)
void __init efi_set_executable(efi_memory_desc_t *md, bool executable)
{
u64 addr, npages;
addr = md->virt_addr;
npages = md->num_pages;
memrange_efi_to_native(&addr, &npages);
if (executable)
set_memory_x(addr, npages);
else
set_memory_nx(addr, npages);
}
void __init runtime_code_page_mkexec(void)
{
efi_memory_desc_t *md;
/* Make EFI runtime service code area executable */
for_each_efi_memory_desc(md) {
if (md->type != EFI_RUNTIME_SERVICES_CODE)
continue;
efi_set_executable(md, true);
}
}
void __init efi_memory_uc(u64 addr, unsigned long size)
{
unsigned long page_shift = 1UL << EFI_PAGE_SHIFT;
u64 npages;
npages = round_up(size, page_shift) / page_shift;
memrange_efi_to_native(&addr, &npages);
set_memory_uc(addr, npages);
}
void __init old_map_region(efi_memory_desc_t *md)
{
u64 start_pfn, end_pfn, end;
unsigned long size;
void *va;
start_pfn = PFN_DOWN(md->phys_addr);
size = md->num_pages << PAGE_SHIFT;
end = md->phys_addr + size;
end_pfn = PFN_UP(end);
if (pfn_range_is_mapped(start_pfn, end_pfn)) {
va = __va(md->phys_addr);
if (!(md->attribute & EFI_MEMORY_WB))
efi_memory_uc((u64)(unsigned long)va, size);
} else
va = efi_ioremap(md->phys_addr, size,
md->type, md->attribute);
md->virt_addr = (u64) (unsigned long) va;
if (!va)
pr_err("ioremap of 0x%llX failed!\n",
(unsigned long long)md->phys_addr);
}
#endif
/* Merge contiguous regions of the same type and attribute */
static void __init efi_merge_regions(void)
{

View File

@ -29,9 +29,35 @@
#include <asm/io.h>
#include <asm/desc.h>
#include <asm/page.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
#include <asm/efi.h>
void __init efi_map_region(efi_memory_desc_t *md)
{
u64 start_pfn, end_pfn, end;
unsigned long size;
void *va;
start_pfn = PFN_DOWN(md->phys_addr);
size = md->num_pages << PAGE_SHIFT;
end = md->phys_addr + size;
end_pfn = PFN_UP(end);
if (pfn_range_is_mapped(start_pfn, end_pfn)) {
va = __va(md->phys_addr);
if (!(md->attribute & EFI_MEMORY_WB))
set_memory_uc((unsigned long)va, md->num_pages);
} else {
va = ioremap_cache(md->phys_addr, size);
}
md->virt_addr = (unsigned long)va;
if (!va)
pr_err("ioremap of 0x%llX failed!\n", md->phys_addr);
}
/*
* To make EFI call EFI runtime service in physical addressing mode we need
* prolog/epilog before/after the invocation to claim the EFI runtime service
@ -58,11 +84,6 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
return 0;
}
void __init efi_map_region(efi_memory_desc_t *md)
{
old_map_region(md);
}
void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
@ -107,6 +128,15 @@ efi_status_t __init efi_set_virtual_address_map(unsigned long memory_map_size,
void __init efi_runtime_update_mappings(void)
{
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
if (__supported_pte_mask & _PAGE_NX) {
efi_memory_desc_t *md;
/* Make EFI runtime service code area executable */
for_each_efi_memory_desc(md) {
if (md->type != EFI_RUNTIME_SERVICES_CODE)
continue;
set_memory_x(md->virt_addr, md->num_pages);
}
}
}

View File

@ -259,6 +259,8 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
npages = (__end_rodata - __start_rodata) >> PAGE_SHIFT;
rodata = __pa(__start_rodata);
pfn = rodata >> PAGE_SHIFT;
pf = _PAGE_NX | _PAGE_ENC;
if (kernel_map_pages_in_pgd(pgd, pfn, rodata, npages, pf)) {
pr_err("Failed to map kernel rodata 1:1\n");
return 1;

View File

@ -381,6 +381,7 @@ static int __init efisubsys_init(void)
efi_kobj = kobject_create_and_add("efi", firmware_kobj);
if (!efi_kobj) {
pr_err("efi: Firmware registration failed.\n");
destroy_workqueue(efi_rts_wq);
return -ENOMEM;
}
@ -424,6 +425,7 @@ err_unregister:
generic_ops_unregister();
err_put:
kobject_put(efi_kobj);
destroy_workqueue(efi_rts_wq);
return error;
}

View File

@ -187,20 +187,28 @@ int efi_printk(const char *fmt, ...)
*/
efi_status_t efi_parse_options(char const *cmdline)
{
size_t len = strlen(cmdline) + 1;
size_t len;
efi_status_t status;
char *str, *buf;
if (!cmdline)
return EFI_SUCCESS;
len = strnlen(cmdline, COMMAND_LINE_SIZE - 1) + 1;
status = efi_bs_call(allocate_pool, EFI_LOADER_DATA, len, (void **)&buf);
if (status != EFI_SUCCESS)
return status;
str = skip_spaces(memcpy(buf, cmdline, len));
memcpy(buf, cmdline, len - 1);
buf[len - 1] = '\0';
str = skip_spaces(buf);
while (*str) {
char *param, *val;
str = next_arg(str, &param, &val);
if (!val && !strcmp(param, "--"))
break;
if (!strcmp(param, "nokaslr")) {
efi_nokaslr = true;