Re: [PATCH] mm, kasan: don't poison boot memory
From: Mike Rapoport
Date: Thu Feb 25 2021 - 12:55:32 EST
On Thu, Feb 25, 2021 at 11:31:04AM -0500, George Kennedy wrote:
>
>
>
On 2/25/2021 11:07 AM, Mike Rapoport wrote:
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> 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);
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>
>
> 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.
Right, but I think it parses table description of the other tables and
populates local tables with them.
I think the problem is with how I compare the signatures, please see below
>
[ 0.064317] ACPI: Early table checksum verification disabled
>
[ 0.065437] XXX acpi_tb_parse_root_table: rsdp_address=bfbfa014
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[ 0.066612] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
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[ 0.067759] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS BXPCFACP
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00000001 01000013)
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[ 0.069470] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS BXPCFACP
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00000001 BXPC 00000001)
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[ 0.071183] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS BXPCDSDT
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00000001 BXPC 00000001)
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[ 0.072876] ACPI: FACS 0x00000000BFBFD000 000040
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[ 0.073806] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS BXPCAPIC
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00000001 BXPC 00000001)
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[ 0.075501] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS BXPCHPET
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00000001 BXPC 00000001)
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[ 0.077194] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL EDK2
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00000002 01000013)
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[ 0.078880] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP
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00000000 00000000)
>
[ 0.080588] ACPI: Local APIC address 0xfee00000
>
>
diff --git a/drivers/acpi/acpica/tbutils.c b/drivers/acpi/acpica/tbutils.c
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index dfe1ac3..603b3a8 100644
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--- a/drivers/acpi/acpica/tbutils.c
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+++ b/drivers/acpi/acpica/tbutils.c
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@@ -7,6 +7,8 @@
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*
>
*****************************************************************************/
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>
+#include <linux/memblock.h>
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+
>
#include <acpi/acpi.h>
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#include "accommon.h"
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#include "actables.h"
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@@ -232,6 +234,8 @@ struct acpi_table_header *acpi_tb_copy_dsdt(u32
>
table_index)
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acpi_status status;
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u32 table_index;
>
>
+printk(KERN_ERR "XXX acpi_tb_parse_root_table: rsdp_address=%llx\n",
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rsdp_address);
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+
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ACPI_FUNCTION_TRACE(tb_parse_root_table);
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>
/* Map the entire RSDP and extract the address of the RSDT or XSDT */
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@@ -339,6 +343,22 @@ struct acpi_table_header *acpi_tb_copy_dsdt(u32
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table_index)
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acpi_tb_parse_fadt();
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}
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>
+ if (ACPI_SUCCESS(status) &&
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+ ACPI_COMPARE_NAMESEG(&acpi_gbl_root_table_list.
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+ tables[table_index].signature,
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+ ACPI_SIG_IBFT)) {
We have:
include/acpi/actbl1.h:#define ACPI_SIG_IBFT "IBFT" /* iSCSI Boot Firmware Table */
and the BIOS uses "iBFT", so we need to loop over possible signature
variants like iscsi_ibft_find does.
Do you mind replacing ACPI_SIG_IBFT with "iBFT" and try again?
>
+ struct acpi_table_header *ibft;
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+ struct acpi_table_desc *desc;
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+
>
+ desc = &acpi_gbl_root_table_list.tables[table_index];
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+ status = acpi_tb_get_table(desc, &ibft);
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+ if (ACPI_SUCCESS(status)) {
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+printk(KERN_ERR "XXX acpi_tb_parse_root_table(calling memblock_reserve()):
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addres=%llx, ibft->length=%x\n", address, ibft->length);
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+ memblock_reserve(address, ibft->length);
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+ acpi_tb_put_table(desc);
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+ }
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+ }
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+
>
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
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> > [ 30.308890] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>
> > 0.0.0 02/06/2015
>
> > [ 30.308890] Call Trace:
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> > [ 30.308890] dump_stack+0xdb/0x120
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> > [ 30.308890] ? ibft_init+0x134/0xc33
>
> > [ 30.308890] print_address_description.constprop.7+0x41/0x60
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> > [ 30.308890] ? ibft_init+0x134/0xc33
>
> > [ 30.308890] ? ibft_init+0x134/0xc33
>
> > [ 30.308890] kasan_report.cold.10+0x78/0xd1
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> > [ 30.308890] ? ibft_init+0x134/0xc33
>
> > [ 30.308890] __asan_report_load_n_noabort+0xf/0x20
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> > [ 30.308890] ibft_init+0x134/0xc33
>
> > [ 30.308890] ? write_comp_data+0x2f/0x90
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> > [ 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:
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> > [ 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
>
> >
>
--
Sincerely yours,
Mike.