FYI, we noticed the following commit:

commit: 98f77489678c1531207c74aec3089a8647b662db ("KEYS: sanitize add_key() and keyctl() key payloads")
https://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git master

in testcase: trinity
with following parameters:

	runtime: 300s

test-description: Trinity is a linux system call fuzz tester.
test-url: http://codemonkey.org.uk/projects/trinity/


on test machine: qemu-system-x86_64 -enable-kvm -cpu IvyBridge -m 420M

caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):


+------------------------------------------+------------+------------+
|                                          | 8979b02aaf | 98f7748967 |
+------------------------------------------+------------+------------+
| boot_successes                           | 47         | 16         |
| boot_failures                            | 0          | 28         |
| BUG:unable_to_handle_kernel              | 0          | 28         |
| Oops:#[##]                               | 0          | 28         |
| Kernel_panic-not_syncing:Fatal_exception | 0          | 28         |
+------------------------------------------+------------+------------+



[   16.476188] BUG: unable to handle kernel NULL pointer dereference at           (null)
[   16.478886] IP: memset_erms+0x9/0x10
[   16.480180] PGD a9a067 
[   16.480181] PUD a9b067 
[   16.481283] PMD 0 
[   16.482389] 
[   16.484358] Oops: 0002 [#1] SMP
[   16.485573] Modules linked in: pptp gre l2tp_ppp l2tp_netlink l2tp_core ip6_udp_tunnel udp_tunnel pppoe pppox ppp_generic slhc nfnetlink scsi_transport_iscsi dccp_ipv6 atm sctp dccp_ipv4 dccp
[   16.490424] CPU: 0 PID: 311 Comm: trinity-c2 Not tainted 4.11.0-rc4-00106-g98f7748 #1
[   16.493066] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.3-20161025_171302-gandalf 04/01/2014
[   16.496072] task: ffff8800195425c0 task.stack: ffffc90000338000
[   16.499768] RIP: 0010:memset_erms+0x9/0x10
[   16.501145] RSP: 0018:ffffc9000033bea8 EFLAGS: 00010246
[   16.502717] RAX: ffffffffffffff00 RBX: 0000000000000000 RCX: 0000000000000001
[   16.504650] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000
[   16.506550] RBP: ffffc9000033beb8 R08: 0000000000000020 R09: 0000000000000000
[   16.508420] R10: 8080808080808080 R11: fefefefefefefeff R12: ffffffffffffff82
[   16.510312] R13: 0000000000000000 R14: 0000000000000000 R15: ffffffffffffff82
[   16.512193] FS:  0000000000000000(0000) GS:ffff88000be00000(0063) knlGS:0000000009cf1840
[   16.514822] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[   16.516468] CR2: 0000000000000000 CR3: 0000000000a99000 CR4: 00000000001406f0
[   16.518369] Call Trace:
[   16.519468]  ? memzero_explicit+0x12/0x20
[   16.520838]  SyS_add_key+0x14c/0x1f0
[   16.522133]  do_fast_syscall_32+0xab/0x250
[   16.523508]  entry_SYSENTER_compat+0x4c/0x5b
[   16.524913] RIP: 0023:0xf77d5c99
[   16.526137] RSP: 002b:00000000ffccaf0c EFLAGS: 00000292 ORIG_RAX: 000000000000011e
[   16.544091] RAX: ffffffffffffffda RBX: 00000000080ecb3d RCX: 0000000000000000
[   16.545969] RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00000000102100a5
[   16.547857] RBP: 0000000040000000 R08: 0000000000000000 R09: 0000000000000000
[   16.549732] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[   16.551615] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[   16.553491] Code: 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 
[   16.558559] RIP: memset_erms+0x9/0x10 RSP: ffffc9000033bea8
[   16.560177] CR2: 0000000000000000
[   16.561464] ---[ end trace 9432180228dd30ad ]---


To reproduce:

        git clone https://github.com/01org/lkp-tests.git
        cd lkp-tests
        bin/lkp qemu -k <bzImage> job-script  # job-script is attached in this email



Thanks,
Xiaolong