KASAN: stack-out-of-bounds Read in acpi_nfit

KASAN: stack-out-of-bounds Read in acpi_nfit_ctl
Status: upstream: reported C repro on 2019/12/16 18:55
Reported-by: syzbot+2812ea3c67cdf329dde3@syzkaller.appspotmail.com
First crash: 446d, last: 416d

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2020/09/08 21:37	46m	brookebasile@gmail.com		upstream	OK

Sample crash report:

==================================================================
BUG: KASAN: stack-out-of-bounds in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
BUG: KASAN: stack-out-of-bounds in acpi_nfit_ctl+0x47f/0x1840 drivers/acpi/nfit/core.c:495
Read of size 8 at addr ffffc90003267bd0 by task syz-executor077/8537

CPU: 2 PID: 8537 Comm: syz-executor077 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
 acpi_nfit_ctl+0x47f/0x1840 drivers/acpi/nfit/core.c:495
 __nd_ioctl drivers/nvdimm/bus.c:1152 [inline]
 nd_ioctl.isra.0+0xfe2/0x1580 drivers/nvdimm/bus.c:1230
 bus_ioctl+0x59/0x70 drivers/nvdimm/bus.c:1242
 compat_ptr_ioctl+0x6e/0xa0 fs/ioctl.c:788
 __do_compat_sys_ioctl fs/compat_ioctl.c:214 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:142 [inline]
 __ia32_compat_sys_ioctl+0x233/0x610 fs/compat_ioctl.c:142
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f12a39
Code: 00 00 00 89 d3 5b 5e 5f 5d c3 b8 80 96 98 00 eb c4 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ff8ed9cc EFLAGS: 00000213 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000004018920a
RDX: 00000000200001c0 RSI: 00000000ff8eda20 RDI: 00000000080481b0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000


addr ffffc90003267bd0 is located in stack of task syz-executor077/8537 at offset 88 in frame:
 acpi_nfit_ctl+0x0/0x1840 drivers/acpi/nfit/core.c:288

this frame has 5 objects:
 [32, 40) 'cmd_mask'
 [64, 72) 'dsm_mask'
 [96, 112) 'buf'
 [128, 152) 'in_obj'
 [192, 216) 'in_buf'

Memory state around the buggy address:
 ffffc90003267a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90003267b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1
>ffffc90003267b80: f1 f1 f1 00 f2 f2 f2 00 f2 f2 f2 00 00 f2 f2 00
                                                 ^
 ffffc90003267c00: 00 00 f2 f2 f2 f2 f2 00 00 00 f3 f3 f3 f3 f3 00
 ffffc90003267c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (2):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Title
ci-qemu-upstream-386	2019/12/16 05:44	upstream	510c9788	eef6e580	.config	log	report	syz	C
ci-qemu-upstream-386	2020/01/15 16:38	upstream	95e20af9	069a5a44	.config	log	report