==================================================================
BUG: KASAN: slab-out-of-bounds in fscache_set_key fs/fscache/cookie.c:120 [inline]
BUG: KASAN: slab-out-of-bounds in fscache_alloc_cookie+0x7ad/0x880 fs/fscache/cookie.c:171
Read of size 4 at addr ffff8801c3a14f14 by task syz-executor2/7815

CPU: 0 PID: 7815 Comm: syz-executor2 Not tainted 4.19.0-rc8+ #62
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_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 fscache_set_key fs/fscache/cookie.c:120 [inline]
 fscache_alloc_cookie+0x7ad/0x880 fs/fscache/cookie.c:171
input:  as /devices/virtual/input/input29
 __fscache_acquire_cookie+0x230/0xb60 fs/fscache/cookie.c:303
 fscache_acquire_cookie include/linux/fscache.h:338 [inline]
 nfs_fscache_get_client_cookie+0x463/0x600 fs/nfs/fscache.c:85
 nfs_alloc_client+0x563/0x760 fs/nfs/client.c:188
 nfs_get_client+0x8e8/0x14d0 fs/nfs/client.c:430
 nfs_init_server+0x357/0x1010 fs/nfs/client.c:670
 nfs_create_server+0x86/0x5f0 fs/nfs/client.c:954
 nfs_try_mount+0x180/0xa80 fs/nfs/super.c:1884
kobject: 'input29::mail' (000000001965becc): kobject_add_internal: parent: 'input29', set: 'devices'
 nfs_fs_mount+0x17f8/0x2f1c fs/nfs/super.c:2695
kobject: 'input29::mail' (000000001965becc): kobject_uevent_env
 mount_fs+0xae/0x31d fs/super.c:1261
 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961
kobject: 'input29::mail' (000000001965becc): fill_kobj_path: path = '/devices/virtual/input/input29/input29::mail'
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2457 [inline]
 do_mount+0x581/0x31f0 fs/namespace.c:2787
kobject: 'event4' (0000000075c0e007): kobject_add_internal: parent: 'input29', set: 'devices'
 ksys_mount+0x12d/0x140 fs/namespace.c:3003
 __do_sys_mount fs/namespace.c:3017 [inline]
 __se_sys_mount fs/namespace.c:3014 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
kobject: 'event4' (0000000075c0e007): kobject_uevent_env
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
kobject: 'event4' (0000000075c0e007): fill_kobj_path: path = '/devices/virtual/input/input29/event4'
RIP: 0033:0x457569
Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f3f13899c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569
RDX: 000000002015bffc RSI: 0000000020343ff8 RDI: 00000000208deff8
RBP: 000000000072bf00 R08: 000000002000a000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3f1389a6d4
R13: 00000000004c289b R14: 00000000004d3c78 R15: 00000000ffffffff

Allocated by task 7815:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
kobject: 'input29::numlock' (0000000018eb530a): kobject_uevent_env
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc+0x14e/0x760 mm/slab.c:3727
 kmalloc include/linux/slab.h:518 [inline]
 kzalloc include/linux/slab.h:707 [inline]
 fscache_set_key fs/fscache/cookie.c:101 [inline]
 fscache_alloc_cookie+0x6f7/0x880 fs/fscache/cookie.c:171
 __fscache_acquire_cookie+0x230/0xb60 fs/fscache/cookie.c:303
 fscache_acquire_cookie include/linux/fscache.h:338 [inline]
 nfs_fscache_get_client_cookie+0x463/0x600 fs/nfs/fscache.c:85
 nfs_alloc_client+0x563/0x760 fs/nfs/client.c:188
kobject: 'input29::numlock' (0000000018eb530a): fill_kobj_path: path = '/devices/virtual/input/input29/input29::numlock'
 nfs_get_client+0x8e8/0x14d0 fs/nfs/client.c:430
 nfs_init_server+0x357/0x1010 fs/nfs/client.c:670
 nfs_create_server+0x86/0x5f0 fs/nfs/client.c:954
 nfs_try_mount+0x180/0xa80 fs/nfs/super.c:1884
 nfs_fs_mount+0x17f8/0x2f1c fs/nfs/super.c:2695
 mount_fs+0xae/0x31d fs/super.c:1261
 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961
kobject: 'input29::numlock' (0000000018eb530a): kobject_uevent_env
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2457 [inline]
 do_mount+0x581/0x31f0 fs/namespace.c:2787
 ksys_mount+0x12d/0x140 fs/namespace.c:3003
 __do_sys_mount fs/namespace.c:3017 [inline]
 __se_sys_mount fs/namespace.c:3014 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8801c3a14f00
 which belongs to the cache kmalloc-32 of size 32
kobject: 'input29::numlock' (0000000018eb530a): fill_kobj_path: path = '/devices/virtual/input/input29/input29::numlock'
The buggy address is located 20 bytes inside of
 32-byte region [ffff8801c3a14f00, ffff8801c3a14f20)
The buggy address belongs to the page:
page:ffffea00070e8500 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801c3a14fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea00070b7c88 ffff8801da801248 ffff8801da8001c0
raw: ffff8801c3a14fc1 ffff8801c3a14000 000000010000003f 0000000000000000
kobject: 'input29::numlock' (0000000018eb530a): kobject_cleanup, parent           (null)
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c3a14e00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c3a14e80: 05 fc fc fc fc fc fc fc 00 00 01 fc fc fc fc fc
>ffff8801c3a14f00: 00 00 06 fc fc fc fc fc 01 fc fc fc fc fc fc fc
                         ^
 ffff8801c3a14f80: 01 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801c3a15000: fb fb fb fb fb fb fb fc fc fc fc fb fb fb fb fb
==================================================================
kobject: 'input29::numlock' (0000000018eb530a): calling ktype release