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BUG: KASAN: stack-out-of-bounds in memcmp+0xe3/0x160 lib/string.c:861
Read of size 1 at addr ffff8801be63f3b0 by task syz-executor599/5446

CPU: 0 PID: 5446 Comm: syz-executor599 Not tainted 4.19.0-rc5+ #154
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+0x1c4/0x2b4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 memcmp+0xe3/0x160 lib/string.c:861
 strnstr+0x4b/0x70 lib/string.c:934
 __aa_lookupn_ns+0xc1/0x570 security/apparmor/policy_ns.c:209
 aa_lookupn_ns+0x88/0x1e0 security/apparmor/policy_ns.c:240
 aa_fqlookupn_profile+0x1b9/0x1010 security/apparmor/policy.c:468
 fqlookupn_profile+0x80/0xc0 security/apparmor/label.c:1844
 aa_label_strn_parse+0xa3a/0x1230 security/apparmor/label.c:1908
 aa_label_parse+0x42/0x50 security/apparmor/label.c:1943
 aa_change_profile+0x513/0x3510 security/apparmor/domain.c:1362
 apparmor_setprocattr+0xaa4/0x1150 security/apparmor/lsm.c:658
 security_setprocattr+0x66/0xc0 security/security.c:1298
 proc_pid_attr_write+0x301/0x540 fs/proc/base.c:2555
 __vfs_write+0x119/0x9f0 fs/read_write.c:485
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __ia32_sys_write+0x71/0xb0 fs/read_write.c:607
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f34ca9
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 0c 24 c3 8b 1c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 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:00000000ffec38fc EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000040
RDX: 0000000000000009 RSI: 00000000ffec3a44 RDI: 00000000ffec3a4c
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0006f98fc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 ffffffff06f90101 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801be63f280: f2 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 00 00 00
 ffff8801be63f300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801be63f380: 00 00 00 00 00 f1 f1 f1 f1 f8 f2 f2 f2 f2 f2 f2
                                     ^
 ffff8801be63f400: f2 00 f2 f2 f2 f2 f2 f2 f2 f8 f2 f2 f2 f2 f2 f2
 ffff8801be63f480: f2 00 f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 00 00
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