==================================================================
BUG: KASAN: slab-out-of-bounds in ecryptfs_verify_auth_tok_from_key+0x350/0x3a0
Read of size 2 at addr ffff888105b55d99 by task syz.1.13364/5217

CPU: 1 UID: 0 PID: 5217 Comm: syz.1.13364 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_address_description+0x55/0x1e0
 print_report+0x58/0x70
 kasan_report+0x117/0x150
 ecryptfs_verify_auth_tok_from_key+0x350/0x3a0
 ecryptfs_keyring_auth_tok_for_sig+0xec/0x250
 ecryptfs_get_tree+0x563/0x1370
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x319/0xdc0
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f184959e159
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:00007f184a3ad028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1849825fa0 RCX: 00007f184959e159
RDX: 0000200000000480 RSI: 0000200000000000 RDI: 0000200000000400
RBP: 00007f184963506b R08: 0000200000000500 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1849826038 R14: 00007f1849825fa0 R15: 00007ffd6f3f6748
 </TASK>

Allocated by task 1622:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x36b/0x720
 user_preparse+0x9e/0x160
 __key_create_or_update+0x3a9/0xa80
 key_create_or_update+0x42/0x60
 __se_sys_add_key+0x349/0x420
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888105b55d80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes to the right of
 allocated 25-byte region [ffff888105b55d80, ffff888105b55d99)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x105b55
flags: 0x17ff00000000000(node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000000 ffff888100041780 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000400040 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 5367, tgid 5367 (cmp), ts 27707403914
 post_alloc_hook+0x1f9/0x250
 get_page_from_freelist+0x2209/0x2280
 __alloc_frozen_pages_noprof+0x217/0x5a0
 allocate_slab+0x7d/0x620
 refill_objects+0x2d5/0x350
 __pcs_replace_empty_main+0x2c8/0x6c0
 __kmalloc_cache_noprof+0x39b/0x600
 kmem_cache_free+0x156/0x650
 tear_down_vmas+0x31f/0x530
 exit_mmap+0x4ca/0x9f0
 __mmput+0x118/0x420
 setup_new_exec+0x30d/0x360
 load_elf_binary+0xbc0/0x28d0
 bprm_execve+0x930/0x1590
 do_execveat_common+0x4f4/0x670
 __x64_sys_execve+0x97/0xc0
page last free pid 5367 tgid 5367 ts 27707218769 stack trace:
 __free_frozen_pages+0xc93/0xd90
 tlb_finish_mmu+0x13e/0x220
 exit_mmap+0x4b2/0x9f0
 __mmput+0x118/0x420
 setup_new_exec+0x30d/0x360
 load_elf_binary+0xbc0/0x28d0
 bprm_execve+0x930/0x1590
 do_execveat_common+0x4f4/0x670
 __x64_sys_execve+0x97/0xc0
 do_syscall_64+0x166/0x520
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888105b55c80: 00 00 00 00 fc fc fc fc 00 00 00 00 fc fc fc fc
 ffff888105b55d00: 00 00 00 00 fc fc fc fc fa fb fb fb fc fc fc fc
>ffff888105b55d80: 00 00 00 01 fc fc fc fc 00 00 00 00 fc fc fc fc
                            ^
 ffff888105b55e00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888105b55e80: 00 00 03 fc fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================
