[PATCH] mm, kasan: don't poison boot memory
George Kennedy
george.kennedy at oracle.com
Wed Feb 24 09:22:59 EST 2021
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.
[ 30.385207] iscsi: registered transport (iser)
[ 30.387462] iBFT detected.
[ 30.388042]
==================================================================
[ 30.388119] BUG: KASAN: use-after-free in ibft_init+0x134/0xc33
[ 30.388119] Read of size 4 at addr ffff8880be453004 by task swapper/0/1
[ 30.388119]
[ 30.388119] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.11.0-f9593a0 #11
[ 30.388119] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS 0.0.0 02/06/2015
[ 30.388119] Call Trace:
[ 30.388119] dump_stack+0xdb/0x120
[ 30.388119] ? ibft_init+0x134/0xc33
[ 30.388119] print_address_description.constprop.7+0x41/0x60
[ 30.388119] ? ibft_init+0x134/0xc33
[ 30.388119] ? ibft_init+0x134/0xc33
[ 30.388119] kasan_report.cold.10+0x78/0xd1
[ 30.388119] ? ibft_init+0x134/0xc33
[ 30.388119] __asan_report_load_n_noabort+0xf/0x20
[ 30.388119] ibft_init+0x134/0xc33
[ 30.388119] ? write_comp_data+0x2f/0x90
[ 30.388119] ? ibft_check_initiator_for+0x159/0x159
[ 30.388119] ? write_comp_data+0x2f/0x90
[ 30.388119] ? ibft_check_initiator_for+0x159/0x159
[ 30.388119] do_one_initcall+0xc4/0x3e0
[ 30.388119] ? perf_trace_initcall_level+0x3e0/0x3e0
[ 30.388119] ? unpoison_range+0x14/0x40
[ 30.388119] ? ____kasan_kmalloc.constprop.5+0x8f/0xc0
[ 30.388119] ? kernel_init_freeable+0x420/0x652
George
>
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