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dd75080aa8
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Chen Jingwen dd75080aa8 powerpc/kasan: Fix early region not updated correctly 
The shadow's page table is not updated when PTE_RPN_SHIFT is 24
and PAGE_SHIFT is 12. It not only causes false positives but
also false negative as shown the following text.

Fix it by bringing the logic of kasan_early_shadow_page_entry here.

1. False Positive:
==================================================================
BUG: KASAN: vmalloc-out-of-bounds in pcpu_alloc+0x508/0xa50
Write of size 16 at addr f57f3be0 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.15.0-12267-gdebe436e77c7 #1
Call Trace:
[c80d1c20] [c07fe7b8] dump_stack_lvl+0x4c/0x6c (unreliable)
[c80d1c40] [c02ff668] print_address_description.constprop.0+0x88/0x300
[c80d1c70] [c02ff45c] kasan_report+0x1ec/0x200
[c80d1cb0] [c0300b20] kasan_check_range+0x160/0x2f0
[c80d1cc0] [c03018a4] memset+0x34/0x90
[c80d1ce0] [c0280108] pcpu_alloc+0x508/0xa50
[c80d1d40] [c02fd7bc] __kmem_cache_create+0xfc/0x570
[c80d1d70] [c0283d64] kmem_cache_create_usercopy+0x274/0x3e0
[c80d1db0] [c2036580] init_sd+0xc4/0x1d0
[c80d1de0] [c00044a0] do_one_initcall+0xc0/0x33c
[c80d1eb0] [c2001624] kernel_init_freeable+0x2c8/0x384
[c80d1ef0] [c0004b14] kernel_init+0x24/0x170
[c80d1f10] [c001b26c] ret_from_kernel_thread+0x5c/0x64

Memory state around the buggy address:
 f57f3a80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 f57f3b00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
>f57f3b80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
                                               ^
 f57f3c00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
 f57f3c80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8
==================================================================

2. False Negative (with KASAN tests):
==================================================================
Before fix:
    ok 45 - kmalloc_double_kzfree
    # vmalloc_oob: EXPECTATION FAILED at lib/test_kasan.c:1039
    KASAN failure expected in "((volatile char *)area)[3100]", but none occurred
    not ok 46 - vmalloc_oob
    not ok 1 - kasan

==================================================================
After fix:
    ok 1 - kasan

Fixes: cbd18991e2 ("powerpc/mm: Fix an Oops in kasan_mmu_init()")
Cc: stable@vger.kernel.org # 5.4.x
Signed-off-by: Chen Jingwen <chenjingwen6@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211229035226.59159-1-chenjingwen6@huawei.com
2022-02-03 22:37:44 +11:00
..
boot powerpc: dts: t1040rdb: fix ports names for Seville Ethernet switch 2022-02-02 20:32:10 +11:00
configs RTC for 5.17 2022-01-21 13:13:35 +02:00
crypto powerpc updates for 5.17 2022-01-14 15:17:26 +01:00
include powerpc/epapr: Fix parmeters typo 2022-02-03 21:35:56 +11:00
kernel powerpc/module_64: use module_init_section instead of patching names 2022-02-03 22:20:37 +11:00
kexec powerpc/kernel: Add __init attribute to eligible functions 2021-12-23 22:33:10 +11:00
kvm KVM: PPC: Book3S HV Nested: Fix nested HFSCR being clobbered with multiple vCPUs 2022-01-25 16:39:41 +11:00
lib powerpc/32: Fix boot failure with GCC latent entropy plugin 2021-12-23 22:36:58 +11:00
math-emu powerpc/64s: avoid reloading (H)SRR registers if they are still valid 2021-06-25 00:06:55 +10:00
mm powerpc/kasan: Fix early region not updated correctly 2022-02-03 22:37:44 +11:00
net powerpc64/bpf: Limit 'ldbrx' to processors compliant with ISA v2.06 2022-01-15 12:21:25 +11:00
perf powerpc/perf: Don't use perf_hw_context for trace IMC PMU 2022-02-03 22:32:54 +11:00
platforms powerpc/spufs: adjust list element pointer type 2022-02-03 21:40:32 +11:00
purgatory powerpc/kexec: Don't use .machine ppc64 in trampoline_64.S 2021-04-08 21:17:43 +10:00
sysdev powerpc/xive: Add some error handling code to 'xive_spapr_init()' 2022-02-03 22:36:59 +11:00
tools powerpc/head_check: Fix shellcheck errors 2021-08-17 22:52:02 +10:00
xmon powerpc/xmon: Dump XIVE information for online-only processors. 2022-01-06 21:47:00 +11:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig Merge branch 'akpm' (patches from Andrew) 2022-01-20 10:41:01 +02:00
Kconfig.debug powerpc/ptdump: Convert powerpc to GENERIC_PTDUMP 2021-08-25 13:35:48 +10:00
Makefile powerpc: check for support for -Wa,-m{power4,any} 2021-12-23 22:35:12 +11:00
Makefile.postlink powerpc: unrel_branch_check.sh: use nm to find symbol value 2020-09-02 11:00:22 +10:00