==================================================================
BUG: KASAN: slab-out-of-bounds in ecryptfs_verify_auth_tok_from_key+0x3b7/0x400 fs/ecryptfs/keystore.c:465
Read of size 2 at addr ffff888023963e98 by task syz.0.17/5919

CPU: 1 UID: 0 PID: 5919 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x13d/0x4b0 mm/kasan/report.c:482
 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
 ecryptfs_verify_auth_tok_from_key+0x3b7/0x400 fs/ecryptfs/keystore.c:465
 ecryptfs_keyring_auth_tok_for_sig+0x9e/0x1f0 fs/ecryptfs/keystore.c:1606
 ecryptfs_init_global_auth_toks fs/ecryptfs/main.c:194 [inline]
 ecryptfs_validate_options fs/ecryptfs/main.c:420 [inline]
 ecryptfs_get_tree+0x57b/0x15b0 fs/ecryptfs/main.c:453
 vfs_get_tree+0x92/0x320 fs/super.c:1932
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3772 [inline]
 do_new_mount fs/namespace.c:3848 [inline]
 path_mount+0x7d0/0x24c0 fs/namespace.c:4168
 do_mount fs/namespace.c:4181 [inline]
 __do_sys_mount fs/namespace.c:4397 [inline]
 __se_sys_mount fs/namespace.c:4374 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4374
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6bca59e1d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffebe637d18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f6bca825fa0 RCX: 00007f6bca59e1d9
RDX: 0000200000000480 RSI: 0000200000000000 RDI: 0000200000000400
RBP: 00007f6bca635888 R08: 0000200000000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6bca825fac R14: 00007f6bca825fa0 R15: 00007f6bca825fa0
 </TASK>

Allocated by task 5919:
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5414 [inline]
 __kmalloc_noprof+0x32f/0x840 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 user_preparse+0x9b/0x1c0 security/keys/user_defined.c:67
 __key_create_or_update+0x413/0xe30 security/keys/key.c:854
 key_create_or_update+0x42/0x60 security/keys/key.c:1021
 __do_sys_add_key+0x2e8/0x460 security/keys/keyctl.c:134
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888023963e80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of
 allocated 25-byte region [ffff888023963e80, ffff888023963e99)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888023963f00 pfn:0x23963
flags: 0xfff00000000200(workingset|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000200 ffff88801d042780 ffffea0000b185d0 ffffea000096fb50
raw: ffff888023963f00 000000000040003f 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 614, tgid 614 (kworker/u33:7), ts 5139614268
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x2eb/0x3300 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab mm/slub.c:3462 [inline]
 new_slab+0xa9/0x6e0 mm/slub.c:3513
 refill_objects+0xe3/0x410 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 slab_free_hook mm/slub.c:2700 [inline]
 slab_free mm/slub.c:6509 [inline]
 kmem_cache_free+0x40f/0x6c0 mm/slub.c:6636
 file_free fs/file_table.c:104 [inline]
 __fput_deferred+0x3e9/0x4a0 fs/file_table.c:567
 fput_close+0x118/0x250 fs/file_table.c:629
 path_openat+0x1033/0x2440 fs/namei.c:5009
 do_file_open+0x20e/0x430 fs/namei.c:5029
 do_open_execat+0xd1/0x360 fs/exec.c:786
 alloc_bprm+0x2d/0x9e0 fs/exec.c:1516
 class_bprm_constructor fs/exec.c:1581 [inline]
 kernel_execve+0x8f/0x3a0 fs/exec.c:1978
 call_usermodehelper_exec_async+0x239/0x4b0 kernel/umh.c:107
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888023963d80: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff888023963e00: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
>ffff888023963e80: 00 00 00 01 fc fc fc fc fa fb fb fb fc fc fc fc
                            ^
 ffff888023963f00: fa fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff888023963f80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================