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SubjectRe: [PATCH] mm, kasan: don't poison boot memory
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On 2/25/2021 9:57 AM, Mike Rapoport wrote:
> On Thu, Feb 25, 2021 at 07:38:19AM -0500, George Kennedy wrote:
>> On 2/25/2021 3:53 AM, Mike Rapoport wrote:
>>> Hi George,
>>>
>>>> On 2/24/2021 5:37 AM, Mike Rapoport wrote:
>>>>> On Tue, Feb 23, 2021 at 04:46:28PM -0500, George Kennedy wrote:
>>>>>> Mike,
>>>>>>
>>>>>> Still no luck.
>>>>>>
>>>>>> [   30.193723] iscsi: registered transport (iser)
>>>>>> [   30.195970] iBFT detected.
>>>>>> [   30.196571] BUG: unable to handle page fault for address: ffffffffff240004
>>>>> Hmm, we cannot set ibft_addr to early pointer to the ACPI table.
>>>>> Let's try something more disruptive and move the reservation back to
>>>>> iscsi_ibft_find.c.
>>>>>
>>>>> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
>>>>> index 7bdc0239a943..c118dd54a747 100644
>>>>> --- a/arch/x86/kernel/acpi/boot.c
>>>>> +++ b/arch/x86/kernel/acpi/boot.c
>>>>> @@ -1551,6 +1551,7 @@ void __init acpi_boot_table_init(void)
>>>>> if (acpi_disabled)
>>>>> return;
>>>>> +#if 0
>>>>> /*
>>>>> * Initialize the ACPI boot-time table parser.
>>>>> */
>>>>> @@ -1558,6 +1559,7 @@ void __init acpi_boot_table_init(void)
>>>>> disable_acpi();
>>>>> return;
>>>>> }
>>>>> +#endif
>>>>> acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
>>>>> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
>>>>> index d883176ef2ce..c615ce96c9a2 100644
>>>>> --- a/arch/x86/kernel/setup.c
>>>>> +++ b/arch/x86/kernel/setup.c
>>>>> @@ -570,16 +570,6 @@ void __init reserve_standard_io_resources(void)
>>>>> }
>>>>> -static __init void reserve_ibft_region(void)
>>>>> -{
>>>>> - unsigned long addr, size = 0;
>>>>> -
>>>>> - addr = find_ibft_region(&size);
>>>>> -
>>>>> - if (size)
>>>>> - memblock_reserve(addr, size);
>>>>> -}
>>>>> -
>>>>> static bool __init snb_gfx_workaround_needed(void)
>>>>> {
>>>>> #ifdef CONFIG_PCI
>>>>> @@ -1032,6 +1022,12 @@ void __init setup_arch(char **cmdline_p)
>>>>> */
>>>>> find_smp_config();
>>>>> + /*
>>>>> + * Initialize the ACPI boot-time table parser.
>>>>> + */
>>>>> + if (acpi_table_init())
>>>>> + disable_acpi();
>>>>> +
>>>>> reserve_ibft_region();
>>>>> early_alloc_pgt_buf();
>>>>> diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
>>>>> index 64bb94523281..01be513843d6 100644
>>>>> --- a/drivers/firmware/iscsi_ibft_find.c
>>>>> +++ b/drivers/firmware/iscsi_ibft_find.c
>>>>> @@ -47,7 +47,25 @@ static const struct {
>>>>> #define VGA_MEM 0xA0000 /* VGA buffer */
>>>>> #define VGA_SIZE 0x20000 /* 128kB */
>>>>> -static int __init find_ibft_in_mem(void)
>>>>> +static void __init *acpi_find_ibft_region(void)
>>>>> +{
>>>>> + int i;
>>>>> + struct acpi_table_header *table = NULL;
>>>>> + acpi_status status;
>>>>> +
>>>>> + if (acpi_disabled)
>>>>> + return NULL;
>>>>> +
>>>>> + for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++) {
>>>>> + status = acpi_get_table(ibft_signs[i].sign, 0, &table);
>>>>> + if (ACPI_SUCCESS(status))
>>>>> + return table;
>>>>> + }
>>>>> +
>>>>> + return NULL;
>>>>> +}
>>>>> +
>>>>> +static void __init *find_ibft_in_mem(void)
>>>>> {
>>>>> unsigned long pos;
>>>>> unsigned int len = 0;
>>>>> @@ -70,35 +88,44 @@ static int __init find_ibft_in_mem(void)
>>>>> /* if the length of the table extends past 1M,
>>>>> * the table cannot be valid. */
>>>>> if (pos + len <= (IBFT_END-1)) {
>>>>> - ibft_addr = (struct acpi_table_ibft *)virt;
>>>>> pr_info("iBFT found at 0x%lx.\n", pos);
>>>>> - goto done;
>>>>> + return virt;
>>>>> }
>>>>> }
>>>>> }
>>>>> }
>>>>> -done:
>>>>> - return len;
>>>>> +
>>>>> + return NULL;
>>>>> }
>>>>> +
>>>>> +static void __init *find_ibft(void)
>>>>> +{
>>>>> + /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
>>>>> + * only use ACPI for this */
>>>>> + if (!efi_enabled(EFI_BOOT))
>>>>> + return find_ibft_in_mem();
>>>>> + else
>>>>> + return acpi_find_ibft_region();
>>>>> +}
>>>>> +
>>>>> /*
>>>>> * Routine used to find the iSCSI Boot Format Table. The logical
>>>>> * kernel address is set in the ibft_addr global variable.
>>>>> */
>>>>> -unsigned long __init find_ibft_region(unsigned long *sizep)
>>>>> +void __init reserve_ibft_region(void)
>>>>> {
>>>>> - ibft_addr = NULL;
>>>>> + struct acpi_table_ibft *table;
>>>>> + unsigned long size;
>>>>> - /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
>>>>> - * only use ACPI for this */
>>>>> + table = find_ibft();
>>>>> + if (!table)
>>>>> + return;
>>>>> - if (!efi_enabled(EFI_BOOT))
>>>>> - find_ibft_in_mem();
>>>>> -
>>>>> - if (ibft_addr) {
>>>>> - *sizep = PAGE_ALIGN(ibft_addr->header.length);
>>>>> - return (u64)virt_to_phys(ibft_addr);
>>>>> - }
>>>>> + size = PAGE_ALIGN(table->header.length);
>>>>> + memblock_reserve(virt_to_phys(table), size);
>>>>> - *sizep = 0;
>>>>> - return 0;
>>>>> + if (efi_enabled(EFI_BOOT))
>>>>> + acpi_put_table(&table->header);
>>>>> + else
>>>>> + ibft_addr = table;
>>>>> }
>>>>> diff --git a/include/linux/iscsi_ibft.h b/include/linux/iscsi_ibft.h
>>>>> index b7b45ca82bea..da813c891990 100644
>>>>> --- a/include/linux/iscsi_ibft.h
>>>>> +++ b/include/linux/iscsi_ibft.h
>>>>> @@ -26,13 +26,9 @@ extern struct acpi_table_ibft *ibft_addr;
>>>>> * mapped address is set in the ibft_addr variable.
>>>>> */
>>>>> #ifdef CONFIG_ISCSI_IBFT_FIND
>>>>> -unsigned long find_ibft_region(unsigned long *sizep);
>>>>> +void reserve_ibft_region(void);
>>>>> #else
>>>>> -static inline unsigned long find_ibft_region(unsigned long *sizep)
>>>>> -{
>>>>> - *sizep = 0;
>>>>> - return 0;
>>>>> -}
>>>>> +static inline void reserve_ibft_region(void) {}
>>>>> #endif
>>>>> #endif /* ISCSI_IBFT_H */
>>>> Still no luck Mike,
>>>>
>>>> We're back to the original problem where the only thing that worked was to
>>>> run "SetPageReserved(page)" before calling "kmap(page)". The page is being
>>>> "freed" before ibft_init() is called as a result of the recent buddy page
>>>> freeing changes.
>>> I keep missing some little details each time :(
>> No worries. Thanks for all your help. Does this patch go on top of your
>> previous patch or is it standalone?
> This is standalone.
>
>> George
>>> Ok, let's try from the different angle.
>>>
>>> diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
>>> index 4b9b329a5a92..ec43e1447336 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"
>>> @@ -339,6 +341,21 @@ acpi_tb_parse_root_table(acpi_physical_address rsdp_address)
>>> 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)) {
>>> + memblock_reserve(address, ibft->length);
>>> + acpi_tb_put_table(desc);
>>> +
>>> + }
>>> +
>>> next_table:
>>> table_entry += table_entry_size;
>>>
>>>
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.

[   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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