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BUG: KASAN: use-after-free in class_equal+0x40/0x50 kernel/locking/lockdep.c:1527
Read of size 8 at addr ffff88807a1c4f80 by task syz-executor.5/9744

CPU: 1 PID: 9744 Comm: syz-executor.5 Not tainted 5.2.0-rc2+ #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:

Allocated by task 8925:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_kmalloc mm/kasan/common.c:489 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462
 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:497
 slab_post_alloc_hook mm/slab.h:437 [inline]
 slab_alloc mm/slab.c:3326 [inline]
 kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3488
 getname_flags fs/namei.c:138 [inline]
 getname_flags+0xd6/0x5b0 fs/namei.c:128
 getname fs/namei.c:209 [inline]
 do_symlinkat+0x8b/0x290 fs/namei.c:4141
 __do_sys_symlink fs/namei.c:4171 [inline]
 __se_sys_symlink fs/namei.c:4169 [inline]
 __x64_sys_symlink+0x59/0x80 fs/namei.c:4169
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8925:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459
 __cache_free mm/slab.c:3432 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3698
 putname+0xef/0x130 fs/namei.c:259
 do_symlinkat+0x181/0x290 fs/namei.c:4159
 __do_sys_symlink fs/namei.c:4171 [inline]
 __se_sys_symlink fs/namei.c:4169 [inline]
 __x64_sys_symlink+0x59/0x80 fs/namei.c:4169
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88807a1c41c0
 which belongs to the cache names_cache of size 4096
The buggy address is located 3520 bytes inside of
 4096-byte region [ffff88807a1c41c0, ffff88807a1c51c0)
The buggy address belongs to the page:
page:ffffea0001e87100 refcount:1 mapcount:0 mapping:ffff8880aa594c40 index:0x0 compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea0002679e88 ffffea0001e87188 ffff8880aa594c40
raw: 0000000000000000 ffff88807a1c41c0 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88807a1c4e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807a1c4f00: fb fb f1 f1 f1 f1 00 f2 f2 f2 00 f2 f2 f2 fb fb
>ffff88807a1c4f80: fb fb 00 00 00 f3 f3 f3 f3 f3 fb fb fb fb fb fb
                   ^
 ffff88807a1c5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807a1c5080: fb fb 00 00 00 00 00 00 00 00 fb fb fb fb fb fb
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