kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 17473 Comm: syz-executor2 Not tainted 4.19.0-rc8+ #188
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:memcmp+0x28/0x160 lib/string.c:856
Code: 00 00 48 85 d2 0f 84 0a 01 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 f9 48 89 e5 48 c1 e9 03 41 54 53 48 89 fb 48 83 ec 18 <0f> b6 04 01 48 89 f9 83 e1 07 38 c8 7f 08 84 c0 0f 85 98 00 00 00
RSP: 0018:ffff880194bd6f48 EFLAGS: 00010296
RAX: dffffc0000000000 RBX: 1ffff1003297ae3e RCX: 03fffe200652f5c7
RDX: 0000000000000002 RSI: ffffffff883ba280 RDI: 1ffff1003297ae3e
RBP: ffff880194bd6f70 R08: ffff88018ad7e340 R09: ffffed003b5e4732
kobject: 'loop0' (00000000a9b1b211): kobject_uevent_env
R10: ffffed003b5e4732 R11: ffff8801daf23993 R12: 0000000000000002
R13: ffffffff883ba280 R14: 1fff7901c755213e R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801daf00000(0063) knlGS:00000000f5f96b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000000814b000 CR3: 00000001c6cba000 CR4: 00000000001406e0
Call Trace:
 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+0x513/0x3260 security/apparmor/domain.c:1362
 apparmor_setprocattr+0xa8b/0x1150 security/apparmor/lsm.c:656
 security_setprocattr+0x66/0xc0 security/security.c:1298
 proc_pid_attr_write+0x301/0x540 fs/proc/base.c:2569
 __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: 0023:0xf7f9aca9
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:00000000f5f960cc EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000000
RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
kobject: 'loop0' (00000000a9b1b211): fill_kobj_path: path = '/devices/virtual/block/loop0'
---[ end trace 1df0c53d2fd2bca8 ]---
RIP: 0010:memcmp+0x28/0x160 lib/string.c:856
kobject: 'loop1' (0000000038bee70a): kobject_uevent_env
Code: 00 00 48 85 d2 0f 84 0a 01 00 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 f9 48 89 e5 48 c1 e9 03 41 54 53 48 89 fb 48 83 ec 18 <0f> b6 04 01 48 89 f9 83 e1 07 38 c8 7f 08 84 c0 0f 85 98 00 00 00
kobject: 'loop1' (0000000038bee70a): fill_kobj_path: path = '/devices/virtual/block/loop1'
RSP: 0018:ffff880194bd6f48 EFLAGS: 00010296
kobject: 'loop4' (00000000c23f1dc0): kobject_uevent_env
RAX: dffffc0000000000 RBX: 1ffff1003297ae3e RCX: 03fffe200652f5c7
kobject: 'loop4' (00000000c23f1dc0): fill_kobj_path: path = '/devices/virtual/block/loop4'
RDX: 0000000000000002 RSI: ffffffff883ba280 RDI: 1ffff1003297ae3e
RBP: ffff880194bd6f70 R08: ffff88018ad7e340 R09: ffffed003b5e4732
R10: ffffed003b5e4732 R11: ffff8801daf23993 R12: 0000000000000002
R13: ffffffff883ba280 R14: 1fff7901c755213e R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8801daf00000(0063) knlGS:00000000f5f96b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000625208 CR3: 00000001c6cba000 CR4: 00000000001406e0