[PATCH] mm, kasan: don't poison boot memory

George Kennedy george.kennedy at oracle.com
Thu Feb 25 11:31:04 EST 2021



On 2/25/2021 11:07 AM, Mike Rapoport wrote:
> On Thu, Feb 25, 2021 at 10:22:44AM -0500, George Kennedy wrote:
>>>>>> On 2/24/2021 5:37 AM, Mike Rapoport wrote:
>> Applied just your latest patch, but same failure.
>>
>> I thought there was an earlier comment (which I can't find now) that stated
>> that memblock_reserve() wouldn't reserve the page, which is what's needed
>> here.
> Actually, I think that memblock_reserve() should be just fine, but it seems
> I'm missing something in address calculation each time.
>
> What would happen if you stuck
>
> 	memblock_reserve(0xbe453000, PAGE_SIZE);
>
> say, at the beginning of find_ibft_region()?

Added debug to your patch and this is all that shows up. Looks like the 
patch is in the wrong place as acpi_tb_parse_root_table() is only called 
for the RSDP address.

[    0.064317] ACPI: Early table checksum verification disabled
[    0.065437] XXX acpi_tb_parse_root_table: rsdp_address=bfbfa014
[    0.066612] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
[    0.067759] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS BXPCFACP 
00000001      01000013)
[    0.069470] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS BXPCFACP 
00000001 BXPC 00000001)
[    0.071183] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS BXPCDSDT 
00000001 BXPC 00000001)
[    0.072876] ACPI: FACS 0x00000000BFBFD000 000040
[    0.073806] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS BXPCAPIC 
00000001 BXPC 00000001)
[    0.075501] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS BXPCHPET 
00000001 BXPC 00000001)
[    0.077194] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL EDK2     
00000002      01000013)
[    0.078880] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP 
00000000      00000000)
[    0.080588] ACPI: Local APIC address 0xfee00000

diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
index dfe1ac3..603b3a8 100644
--- a/drivers/acpi/acpica/tbutils.c
+++ b/drivers/acpi/acpica/tbutils.c
@@ -7,6 +7,8 @@
   *
*****************************************************************************/

+#include <linux/memblock.h>
+
  #include <acpi/acpi.h>
  #include "accommon.h"
  #include "actables.h"
@@ -232,6 +234,8 @@ struct acpi_table_header *acpi_tb_copy_dsdt(u32 
table_index)
      acpi_status status;
      u32 table_index;

+printk(KERN_ERR "XXX acpi_tb_parse_root_table: rsdp_address=%llx\n", 
rsdp_address);
+
      ACPI_FUNCTION_TRACE(tb_parse_root_table);

      /* Map the entire RSDP and extract the address of the RSDT or XSDT */
@@ -339,6 +343,22 @@ struct acpi_table_header *acpi_tb_copy_dsdt(u32 
table_index)
              acpi_tb_parse_fadt();
          }

+        if (ACPI_SUCCESS(status) &&
+            ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
+                     tables[table_index].signature,
+                     ACPI_SIG_IBFT)) {
+            struct acpi_table_header *ibft;
+            struct acpi_table_desc *desc;
+
+            desc = &acpi_gbl_root_table_list.tables[table_index];
+            status = acpi_tb_get_table(desc, &ibft);
+            if (ACPI_SUCCESS(status)) {
+printk(KERN_ERR "XXX acpi_tb_parse_root_table(calling 
memblock_reserve()): addres=%llx, ibft->length=%x\n", address, 
ibft->length);
+                memblock_reserve(address, ibft->length);
+                acpi_tb_put_table(desc);
+            }
+        }
+
  next_table:

          table_entry += table_entry_size;


>   
>> [   30.308229] iBFT detected..
>> [   30.308796]
>> ==================================================================
>> [   30.308890] BUG: KASAN: use-after-free in ibft_init+0x134/0xc33
>> [   30.308890] Read of size 4 at addr ffff8880be453004 by task swapper/0/1
>> [   30.308890]
>> [   30.308890] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.11.0-f9593a0 #12
>> [   30.308890] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>> 0.0.0 02/06/2015
>> [   30.308890] Call Trace:
>> [   30.308890]  dump_stack+0xdb/0x120
>> [   30.308890]  ? ibft_init+0x134/0xc33
>> [   30.308890]  print_address_description.constprop.7+0x41/0x60
>> [   30.308890]  ? ibft_init+0x134/0xc33
>> [   30.308890]  ? ibft_init+0x134/0xc33
>> [   30.308890]  kasan_report.cold.10+0x78/0xd1
>> [   30.308890]  ? ibft_init+0x134/0xc33
>> [   30.308890]  __asan_report_load_n_noabort+0xf/0x20
>> [   30.308890]  ibft_init+0x134/0xc33
>> [   30.308890]  ? write_comp_data+0x2f/0x90
>> [   30.308890]  ? ibft_check_initiator_for+0x159/0x159
>> [   30.308890]  ? write_comp_data+0x2f/0x90
>> [   30.308890]  ? ibft_check_initiator_for+0x159/0x159
>> [   30.308890]  do_one_initcall+0xc4/0x3e0
>> [   30.308890]  ? perf_trace_initcall_level+0x3e0/0x3e0
>> [   30.308890]  ? unpoison_range+0x14/0x40
>> [   30.308890]  ? ____kasan_kmalloc.constprop.5+0x8f/0xc0
>> [   30.308890]  ? kernel_init_freeable+0x420/0x652
>> [   30.308890]  ? __kasan_kmalloc+0x9/0x10
>> [   30.308890]  ? __sanitizer_cov_trace_pc+0x21/0x50
>> [   30.308890]  kernel_init_freeable+0x596/0x652
>> [   30.308890]  ? console_on_rootfs+0x7d/0x7d
>> [   30.308890]  ? __sanitizer_cov_trace_pc+0x21/0x50
>> [   30.308890]  ? rest_init+0xf0/0xf0
>> [   30.308890]  kernel_init+0x16/0x1d0
>> [   30.308890]  ? rest_init+0xf0/0xf0
>> [   30.308890]  ret_from_fork+0x22/0x30
>> [   30.308890]
>> [   30.308890] The buggy address belongs to the page:
>> [   30.308890] page:0000000001b7b17c refcount:0 mapcount:0
>> mapping:0000000000000000 index:0x1 pfn:0xbe453
>> [   30.308890] flags: 0xfffffc0000000()
>> [   30.308890] raw: 000fffffc0000000 ffffea0002ef9788 ffffea0002f91488
>> 0000000000000000
>> [   30.308890] raw: 0000000000000001 0000000000000000 00000000ffffffff
>> 0000000000000000
>> [   30.308890] page dumped because: kasan: bad access detected
>> [   30.308890] page_owner tracks the page as freed
>> [   30.308890] page last allocated via order 0, migratetype Movable,
>> gfp_mask 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 204, ts 28121288605
>> [   30.308890]  prep_new_page+0xfb/0x140
>> [   30.308890]  get_page_from_freelist+0x3503/0x5730
>> [   30.308890]  __alloc_pages_nodemask+0x2d8/0x650
>> [   30.308890]  alloc_pages_vma+0xe2/0x560
>> [   30.308890]  __handle_mm_fault+0x930/0x26c0
>> [   30.308890]  handle_mm_fault+0x1f9/0x810
>> [   30.308890]  do_user_addr_fault+0x6f7/0xca0
>> [   30.308890]  exc_page_fault+0xaf/0x1a0
>> [   30.308890]  asm_exc_page_fault+0x1e/0x30
>> [   30.308890] page last free stack trace:
>> [   30.308890]  free_pcp_prepare+0x122/0x290
>> [   30.308890]  free_unref_page_list+0xe6/0x490
>> [   30.308890]  release_pages+0x2ed/0x1270
>> [   30.308890]  free_pages_and_swap_cache+0x245/0x2e0
>> [   30.308890]  tlb_flush_mmu+0x11e/0x680
>> [   30.308890]  tlb_finish_mmu+0xa6/0x3e0
>> [   30.308890]  exit_mmap+0x2b3/0x540
>> [   30.308890]  mmput+0x11d/0x450
>> [   30.308890]  do_exit+0xaa6/0x2d40
>> [   30.308890]  do_group_exit+0x128/0x340
>> [   30.308890]  __x64_sys_exit_group+0x43/0x50
>> [   30.308890]  do_syscall_64+0x37/0x50
>> [   30.308890]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
>> [   30.308890]
>> [   30.308890] Memory state around the buggy address:
>> [   30.308890]  ffff8880be452f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>> ff ff
>> [   30.308890]  ffff8880be452f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>> ff ff
>> [   30.308890] >ffff8880be453000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>> ff ff
>> [   30.308890]                    ^
>> [   30.308890]  ffff8880be453080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>> ff ff
>> [   30.308890]  ffff8880be453100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>> ff ff
>> [   30.308890]
>> ==================================================================
>>
>> George
>>




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