[PATCH] mm, kasan: don't poison boot memory
George Kennedy
george.kennedy at oracle.com
Thu Feb 25 20:19:18 EST 2021
On 2/25/2021 12:33 PM, George Kennedy wrote:
>
>
> 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()?
>
> Good news Mike!
>
> The above hack in yesterday's last patch works - 10 successful
> reboots. See: "BE453" below for the hack.
>
> I'll modify the patch to use "table_desc->address" instead, which is
> the physical address of the table.
>
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 7bdc023..c118dd5 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 740f3bdb..b045ab2 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -571,16 +571,6 @@ 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
> @@ -1033,6 +1023,12 @@ 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 64bb945..95fc1a6 100644
> --- a/drivers/firmware/iscsi_ibft_find.c
> +++ b/drivers/firmware/iscsi_ibft_find.c
> @@ -47,7 +47,25 @@
> #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 +88,52 @@ 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);
> +#if 0
> +printk(KERN_ERR "XXX reserve_ibft_region: table=%llx,
> virt_to_phys(table)=%llx, size=%lx\n",
> + (u64)table, virt_to_phys(table), size);
> + memblock_reserve(virt_to_phys(table), size);
> +#else
> +printk(KERN_ERR "XXX reserve_ibft_region: table=%llx,
> 0x00000000BE453000, size=%lx\n",
> + (u64)table, size);
> + memblock_reserve(0x00000000BE453000, size);
> +#endif
>
> - *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 b7b45ca..da813c8 100644
> --- a/include/linux/iscsi_ibft.h
> +++ b/include/linux/iscsi_ibft.h
> @@ -26,13 +26,9 @@
> * 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 */
Mike,
To get rid of the 0x00000000BE453000 hardcoding, I added the following
patch to your above patch to get the iBFT table "address" to use with
memblock_reserve():
diff --git a/drivers/acpi/acpica/tbfind.c b/drivers/acpi/acpica/tbfind.c
index 56d81e4..4bc7bf3 100644
--- a/drivers/acpi/acpica/tbfind.c
+++ b/drivers/acpi/acpica/tbfind.c
@@ -120,3 +120,34 @@
(void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
return_ACPI_STATUS(status);
}
+
+acpi_physical_address
+acpi_tb_find_table_address(char *signature)
+{
+ acpi_physical_address address = 0;
+ struct acpi_table_desc *table_desc;
+ int i;
+
+ ACPI_FUNCTION_TRACE(tb_find_table_address);
+
+printk(KERN_ERR "XXX acpi_tb_find_table_address: signature=%s\n",
signature);
+
+ (void)acpi_ut_acquire_mutex(ACPI_MTX_TABLES);
+ for (i = 0; i < acpi_gbl_root_table_list.current_table_count; ++i) {
+ if (memcmp(&(acpi_gbl_root_table_list.tables[i].signature),
+ signature, ACPI_NAMESEG_SIZE)) {
+
+ /* Not the requested table */
+
+ continue;
+ }
+
+ /* Table with matching signature has been found */
+ table_desc = &acpi_gbl_root_table_list.tables[i];
+ address = table_desc->address;
+ }
+
+ (void)acpi_ut_release_mutex(ACPI_MTX_TABLES);
+printk(KERN_ERR "XXX acpi_tb_find_table_address(EXIT): address=%llx\n",
address);
+ return address;
+}
diff --git a/drivers/firmware/iscsi_ibft_find.c
b/drivers/firmware/iscsi_ibft_find.c
index 95fc1a6..0de70b4 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -28,6 +28,8 @@
#include <asm/mmzone.h>
+extern acpi_physical_address acpi_tb_find_table_address(char *signature);
+
/*
* Physical location of iSCSI Boot Format Table.
*/
@@ -116,24 +118,32 @@ void __init reserve_ibft_region(void)
{
struct acpi_table_ibft *table;
unsigned long size;
+ acpi_physical_address address;
table = find_ibft();
if (!table)
return;
size = PAGE_ALIGN(table->header.length);
+ address = acpi_tb_find_table_address(table->header.signature);
#if 0
printk(KERN_ERR "XXX reserve_ibft_region: table=%llx,
virt_to_phys(table)=%llx, size=%lx\n",
(u64)table, virt_to_phys(table), size);
memblock_reserve(virt_to_phys(table), size);
#else
-printk(KERN_ERR "XXX reserve_ibft_region: table=%llx,
0x00000000BE453000, size=%lx\n",
- (u64)table, size);
- memblock_reserve(0x00000000BE453000, size);
+printk(KERN_ERR "XXX reserve_ibft_region: table=%llx, address=%llx,
size=%lx\n",
+ (u64)table, address, size);
+ if (address)
+ memblock_reserve(address, size);
+ else
+ printk(KERN_ERR "%s: Can't find table address\n", __func__);
#endif
- if (efi_enabled(EFI_BOOT))
+ if (efi_enabled(EFI_BOOT)) {
+printk(KERN_ERR "XXX reserve_ibft_region: calling
acpi_put_table(%llx)\n", (u64)&table->header);
acpi_put_table(&table->header);
- else
+ } else {
ibft_addr = table;
+printk(KERN_ERR "XXX reserve_ibft_region: ibft_addr=%llx\n",
(u64)ibft_addr);
+ }
}
Debug from the above:
[ 0.050646] ACPI: Early table checksum verification disabled
[ 0.051778] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
[ 0.052922] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS BXPCFACP
00000001 01000013)
[ 0.054623] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS BXPCFACP
00000001 BXPC 00000001)
[ 0.056326] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS BXPCDSDT
00000001 BXPC 00000001)
[ 0.058016] ACPI: FACS 0x00000000BFBFD000 000040
[ 0.058940] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS BXPCAPIC
00000001 BXPC 00000001)
[ 0.060627] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS BXPCHPET
00000001 BXPC 00000001)
[ 0.062304] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL EDK2
00000002 01000013)
[ 0.063987] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP
00000000 00000000)
[ 0.065683] XXX acpi_tb_find_table_address: signature=iBFT
[ 0.066754] XXX acpi_tb_find_table_address(EXIT): address=be453000
[ 0.067959] XXX reserve_ibft_region: table=ffffffffff240000,
address=be453000, size=1000
[ 0.069534] XXX reserve_ibft_region: calling
acpi_put_table(ffffffffff240000)
Not sure if it's the right thing to do, but added
"acpi_tb_find_table_address()" to return the physical address of a table
to use with memblock_reserve().
virt_to_phys(table) does not seem to return the physical address for the
iBFT table (it would be nice if struct acpi_table_header also had a
"address" element for the physical address of the table).
Ran 10 successful boots with the above without failure.
George
>
>
> Debug from the above:
>
> [ 0.020293] last_pfn = 0xbfedc max_arch_pfn = 0x400000000
> [ 0.050778] ACPI: Early table checksum verification disabled
> [ 0.056475] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
> [ 0.057628] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS
> BXPCFACP 00000001 01000013)
> [ 0.059341] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS
> BXPCFACP 00000001 BXPC 00000001)
> [ 0.061043] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS
> BXPCDSDT 00000001 BXPC 00000001)
> [ 0.062740] ACPI: FACS 0x00000000BFBFD000 000040
> [ 0.063673] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS
> BXPCAPIC 00000001 BXPC 00000001)
> [ 0.065369] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS
> BXPCHPET 00000001 BXPC 00000001)
> [ 0.067061] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL
> EDK2 00000002 01000013)
> [ 0.068761] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS
> BXPCFACP 00000000 00000000)
> [ 0.070461] XXX reserve_ibft_region: table=ffffffffff240000,
> 0x00000000BE453000, size=1000
> [ 0.072231] check: Scanning 1 areas for low memory corruption
>
> George
>>> [ 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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