[PATCH] mm, kasan: don't poison boot memory
George Kennedy
george.kennedy at oracle.com
Tue Feb 23 16:26:38 EST 2021
On 2/23/2021 3:09 PM, Mike Rapoport wrote:
> On Tue, Feb 23, 2021 at 01:05:05PM -0500, George Kennedy wrote:
>> On 2/23/2021 10:47 AM, Mike Rapoport wrote:
>>
>> It now crashes here:
>>
>> [ 0.051019] ACPI: Early table checksum verification disabled
>> [ 0.056721] ACPI: RSDP 0x00000000BFBFA014 000024 (v02 BOCHS )
>> [ 0.057874] ACPI: XSDT 0x00000000BFBF90E8 00004C (v01 BOCHS BXPCFACP
>> 00000001 01000013)
>> [ 0.059590] ACPI: FACP 0x00000000BFBF5000 000074 (v01 BOCHS BXPCFACP
>> 00000001 BXPC 00000001)
>> [ 0.061306] ACPI: DSDT 0x00000000BFBF6000 00238D (v01 BOCHS BXPCDSDT
>> 00000001 BXPC 00000001)
>> [ 0.063006] ACPI: FACS 0x00000000BFBFD000 000040
>> [ 0.063938] ACPI: APIC 0x00000000BFBF4000 000090 (v01 BOCHS BXPCAPIC
>> 00000001 BXPC 00000001)
>> [ 0.065638] ACPI: HPET 0x00000000BFBF3000 000038 (v01 BOCHS BXPCHPET
>> 00000001 BXPC 00000001)
>> [ 0.067335] ACPI: BGRT 0x00000000BE49B000 000038 (v01 INTEL EDK2
>> 00000002 01000013)
>> [ 0.069030] ACPI: iBFT 0x00000000BE453000 000800 (v01 BOCHS BXPCFACP
>> 00000000 00000000)
>> [ 0.070734] XXX acpi_find_ibft_region:
>> [ 0.071468] XXX iBFT, status=0
>> [ 0.072073] XXX about to call acpi_put_table()...
>> ibft_addr=ffffffffff240000
>> [ 0.073449] XXX acpi_find_ibft_region(EXIT):
>> PANIC: early exception 0x0e IP 10:ffffffff9259f439 error 0 cr2
>> 0xffffffffff240004
> Right, I've missed the dereference of the ibft_addr after
> acpi_find_ibft_region().
>
> With this change to iscsi_ibft_find.c instead of the previous one it should
> be better:
>
> diff --git a/drivers/firmware/iscsi_ibft_find.c b/drivers/firmware/iscsi_ibft_find.c
> index 64bb94523281..1be7481d5c69 100644
> --- a/drivers/firmware/iscsi_ibft_find.c
> +++ b/drivers/firmware/iscsi_ibft_find.c
> @@ -80,6 +80,27 @@ static int __init find_ibft_in_mem(void)
> done:
> return len;
> }
> +
> +static void __init acpi_find_ibft_region(unsigned long *sizep)
> +{
> + int i;
> + struct acpi_table_header *table = NULL;
> + acpi_status status;
> +
> + if (acpi_disabled)
> + return;
> +
> + 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)) {
> + ibft_addr = (struct acpi_table_ibft *)table;
> + *sizep = PAGE_ALIGN(ibft_addr->header.length);
> + acpi_put_table(table);
> + break;
> + }
> + }
> +}
> +
> /*
> * Routine used to find the iSCSI Boot Format Table. The logical
> * kernel address is set in the ibft_addr global variable.
> @@ -91,14 +112,16 @@ unsigned long __init find_ibft_region(unsigned long *sizep)
> /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
> * only use ACPI for this */
>
> - if (!efi_enabled(EFI_BOOT))
> + 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);
> + } else {
> + acpi_find_ibft_region(sizep);
> }
>
> + if (ibft_addr)
> + return (u64)virt_to_phys(ibft_addr);
> +
> *sizep = 0;
> return 0;
> }
Mike,
No luck. Back to the original KASAN ibft_init crash.
I ran with only the above patch from you. Was that what you wanted? Your
previous patch had a section defined out by #if 0. Was that supposed to
be in there as well?
If you need the console output let me know. Got bounced because it was
too large.
[ 30.124650] iBFT detected.
[ 30.125228]
==================================================================
[ 30.126201] BUG: KASAN: use-after-free in ibft_init+0x134/0xc33
[ 30.126201] Read of size 4 at addr ffff8880be453004 by task swapper/0/1
[ 30.126201]
[ 30.126201] CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.11.0-f9593a0 #9
[ 30.126201] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 0.0.0 02/06/2015
[ 30.126201] Call Trace:
[ 30.126201] dump_stack+0xdb/0x120
[ 30.126201] ? ibft_init+0x134/0xc33
[ 30.126201] print_address_description.constprop.7+0x41/0x60
[ 30.126201] ? ibft_init+0x134/0xc33
[ 30.126201] ? ibft_init+0x134/0xc33
[ 30.126201] kasan_report.cold.10+0x78/0xd1
[ 30.126201] ? ibft_init+0x134/0xc33
[ 30.126201] __asan_report_load_n_noabort+0xf/0x20
[ 30.126201] ibft_init+0x134/0xc33
[ 30.126201] ? write_comp_data+0x2f/0x90
[ 30.126201] ? ibft_check_initiator_for+0x159/0x159
[ 30.126201] ? write_comp_data+0x2f/0x90
[ 30.126201] ? ibft_check_initiator_for+0x159/0x159
[ 30.126201] do_one_initcall+0xc4/0x3e0
[ 30.126201] ? perf_trace_initcall_level+0x3e0/0x3e0
[ 30.126201] ? unpoison_range+0x14/0x40
[ 30.126201] ? ____kasan_kmalloc.constprop.5+0x8f/0xc0
[ 30.126201] ? kernel_init_freeable+0x420/0x652
[ 30.126201] ? __kasan_kmalloc+0x9/0x10
[ 30.126201] ? __sanitizer_cov_trace_pc+0x21/0x50
[ 30.126201] kernel_init_freeable+0x596/0x652
[ 30.126201] ? console_on_rootfs+0x7d/0x7d
[ 30.126201] ? __sanitizer_cov_trace_pc+0x21/0x50
[ 30.126201] ? rest_init+0xf0/0xf0
[ 30.126201] kernel_init+0x16/0x1d0
[ 30.126201] ? rest_init+0xf0/0xf0
[ 30.126201] ret_from_fork+0x22/0x30
[ 30.126201]
[ 30.126201] The buggy address belongs to the page:
[ 30.126201] page:0000000091b8f2b4 refcount:0 mapcount:0
mapping:0000000000000000 index:0x1 pfn:0xbe453
[ 30.126201] flags: 0xfffffc0000000()
[ 30.126201] raw: 000fffffc0000000 ffffea0002fac708 ffffea0002fac748
0000000000000000
[ 30.126201] raw: 0000000000000001 0000000000000000 00000000ffffffff
0000000000000000
[ 30.126201] page dumped because: kasan: bad access detected
[ 30.126201] page_owner tracks the page as freed
[ 30.126201] page last allocated via order 0, migratetype Movable,
gfp_mask 0x100dca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), pid 204, ts 27975563827
[ 30.126201] prep_new_page+0xfb/0x140
[ 30.126201] get_page_from_freelist+0x3503/0x5730
[ 30.126201] __alloc_pages_nodemask+0x2d8/0x650
[ 30.126201] alloc_pages_vma+0xe2/0x560
[ 30.126201] __handle_mm_fault+0x930/0x26c0
[ 30.126201] handle_mm_fault+0x1f9/0x810
[ 30.126201] do_user_addr_fault+0x6f7/0xca0
[ 30.126201] exc_page_fault+0xaf/0x1a0
[ 30.126201] asm_exc_page_fault+0x1e/0x30
[ 30.126201] page last free stack trace:
[ 30.126201] free_pcp_prepare+0x122/0x290
[ 30.126201] free_unref_page_list+0xe6/0x490
[ 30.126201] release_pages+0x2ed/0x1270
[ 30.126201] free_pages_and_swap_cache+0x245/0x2e0
[ 30.126201] tlb_flush_mmu+0x11e/0x680
[ 30.126201] tlb_finish_mmu+0xa6/0x3e0
[ 30.126201] exit_mmap+0x2b3/0x540
[ 30.126201] mmput+0x11d/0x450
[ 30.126201] do_exit+0xaa6/0x2d40
[ 30.126201] do_group_exit+0x128/0x340
[ 30.126201] __x64_sys_exit_group+0x43/0x50
[ 30.126201] do_syscall_64+0x37/0x50
[ 30.126201] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 30.126201]
[ 30.126201] Memory state around the buggy address:
[ 30.126201] ffff8880be452f00: ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff
[ 30.126201] ffff8880be452f80: ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff
[ 30.126201] >ffff8880be453000: ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff
[ 30.126201] ^
[ 30.126201] ffff8880be453080: ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff
[ 30.126201] ffff8880be453100: ff ff ff ff ff ff ff ff ff ff ff ff ff
ff ff ff
[ 30.126201]
==================================================================
This is all I ran with:
# git diff
diff --git a/drivers/firmware/iscsi_ibft_find.c
b/drivers/firmware/iscsi_ibft_find.c
index 64bb945..1be7481 100644
--- a/drivers/firmware/iscsi_ibft_find.c
+++ b/drivers/firmware/iscsi_ibft_find.c
@@ -80,6 +80,27 @@ static int __init find_ibft_in_mem(void)
done:
return len;
}
+
+static void __init acpi_find_ibft_region(unsigned long *sizep)
+{
+ int i;
+ struct acpi_table_header *table = NULL;
+ acpi_status status;
+
+ if (acpi_disabled)
+ return;
+
+ 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)) {
+ ibft_addr = (struct acpi_table_ibft *)table;
+ *sizep = PAGE_ALIGN(ibft_addr->header.length);
+ acpi_put_table(table);
+ break;
+ }
+ }
+}
+
/*
* Routine used to find the iSCSI Boot Format Table. The logical
* kernel address is set in the ibft_addr global variable.
@@ -91,14 +112,16 @@ unsigned long __init find_ibft_region(unsigned long
*sizep)
/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
* only use ACPI for this */
- if (!efi_enabled(EFI_BOOT))
+ 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);
+ } else {
+ acpi_find_ibft_region(sizep);
}
+ if (ibft_addr)
+ return (u64)virt_to_phys(ibft_addr);
+
*sizep = 0;
return 0;
}
Thank you,
George
>> [ 0.075711] CPU: 0 PID: 0 Comm: swapper Not tainted 5.11.0-34a2105 #8
>> [ 0.076983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
>> 0.0.0 02/06/2015
>> [ 0.078579] RIP: 0010:find_ibft_region+0x470/0x577
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