KASAN: out-of-bounds Read in unwind_next

KASAN: out-of-bounds Read in unwind_next_frame
Status: upstream: reported syz repro on 2019/01/07 10:01
Reported-by: syzbot+2fdf0ed2b3bc8fc51fc6@syzkaller.appspotmail.com
First crash: 551d, last: 286d

Cause bisection: failed (bisect log)

Fix bisection: failed (bisect log)

similar bugs (6):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
linux-4.14	KASAN: out-of-bounds Read in unwind_next_frame	C	fix	10	45d	288d	0/1	upstream: reported C repro on 2019/09/26 21:20
linux-4.19	KASAN: out-of-bounds Read in unwind_next_frame			1	233d	233d	0/1	auto-closed as invalid on 2020/03/19 23:00
android-49	KASAN: out-of-bounds Read in unwind_next_frame	C		14	639d	455d	0/3	public: reported C repro on 2019/04/13 00:00
android-54	KASAN: out-of-bounds Read in unwind_next_frame			4	26d	75d	0/1	upstream: reported on 2020/04/27 04:09
android-414	KASAN: out-of-bounds Read in unwind_next_frame (2)	C		5	227d	334d	0/1	public: reported C repro on 2019/08/11 14:38
android-414	KASAN: out-of-bounds Read in unwind_next_frame			1	631d	454d	0/1	auto-closed as invalid on 2019/04/28 00:03

Sample crash report:

8021q: adding VLAN 0 to HW filter on device batadv0
==================================================================
BUG: KASAN: out-of-bounds in unwind_next_frame.part.0+0x756/0xa90 arch/x86/kernel/unwind_frame.c:324
Read of size 8 at addr ffff88808b117b68 by task syz-executor4/9315

CPU: 1 PID: 9315 Comm: syz-executor4 Not tainted 5.0.0-rc4+ #53
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135
 unwind_next_frame.part.0+0x756/0xa90 arch/x86/kernel/unwind_frame.c:324
 unwind_next_frame+0x3b/0x50 arch/x86/kernel/unwind_frame.c:287
 __save_stack_trace+0x7a/0xf0 arch/x86/kernel/stacktrace.c:44
 save_stack_trace_tsk arch/x86/kernel/stacktrace.c:76 [inline]
 save_stack_trace_tsk+0x9e/0xd0 arch/x86/kernel/stacktrace.c:69
 proc_pid_stack+0x272/0x430 fs/proc/base.c:438
 proc_single_show+0xf6/0x180 fs/proc/base.c:739
 seq_read+0x4db/0x1130 fs/seq_file.c:229
 do_loop_readv_writev fs/read_write.c:700 [inline]
 do_loop_readv_writev fs/read_write.c:687 [inline]
 do_iter_read+0x4a9/0x660 fs/read_write.c:921
 vfs_readv+0x175/0x1c0 fs/read_write.c:983
 do_preadv+0x1c4/0x280 fs/read_write.c:1067
 __do_sys_preadv fs/read_write.c:1117 [inline]
 __se_sys_preadv fs/read_write.c:1112 [inline]
 __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1112
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458089
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0409b35c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458089
RDX: 2000000000000113 RSI: 0000000020000480 RDI: 0000000000000004
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0409b366d4
R13: 00000000004c4b47 R14: 00000000004d82c0 R15: 00000000ffffffff

The buggy address belongs to the page:
page:ffffea00022c45c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1fffc0000000000()
raw: 01fffc0000000000 0000000000000000 ffffffff022c0101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808b117a00: f1 f1 f1 00 00 f2 f2 00 f2 f2 f2 00 f2 f2 f2 f8
 ffff88808b117a80: f2 f2 f2 f8 f2 f2 f2 f8 f2 f2 f2 f8 f2 f2 f2 f8
>ffff88808b117b00: f2 f2 f2 00 f2 f2 f2 00 f2 f2 f2 00 f3 f3 f3 00
                                                          ^
 ffff88808b117b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808b117c00: 00 00 00 00 00 f1 f1 f1 f1 f1 f1 04 f2 f8 f3 f3
==================================================================

Crashes (12):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	Maintainers
ci-upstream-kasan-gce-smack-root	2019/01/31 13:03	upstream	af0c9af1	aa432daf	.config	log	report	syz	bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-smack-root	2019/01/26 12:06	upstream	ba606975	c73f090a	.config	log	report	syz	bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-selinux-root	2019/09/28 18:58	upstream	f1f2f614	eb6b9855	.config	log	report		bp@alien8.de, hpa@zytor.com, jannh@google.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-selinux-root	2019/09/22 16:56	upstream	f7c3bf8f	d96e88f3	.config	log	report		bp@alien8.de, gregkh@linuxfoundation.org, hpa@zytor.com, jannh@google.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-root	2019/06/21 19:06	upstream	abf02e29	34bf9440	.config	log	report		bp@alien8.de, gregkh@linuxfoundation.org, hpa@zytor.com, jannh@google.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-selinux-root	2019/03/15 02:04	upstream	3b319ee2	d72db19b	.config	log	report		bp@alien8.de, hpa@zytor.com, jannh@google.com, jpoimboe@redhat.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-root	2019/03/08 11:32	upstream	610cd4ea	12365b99	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-smack-root	2019/01/31 12:19	upstream	af0c9af1	aa432daf	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-selinux-root	2019/01/24 04:14	upstream	30bac164	56558f63	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-smack-root	2019/01/23 05:17	upstream	787a3b43	b1ff06b2	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-kasan-gce-selinux-root	2019/01/06 21:13	upstream	b5aef86e	94f8adb5	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org
ci-upstream-linux-next-kasan-gce-root	2019/02/13 20:56	linux-next	c4f3ef3e	0a49c954	.config	log	report		bp@alien8.de, hpa@zytor.com, linux-kernel@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de, x86@kernel.org