audit: type=1400 audit(1592799108.021:8): avc:  denied  { execmem } for  pid=6320 comm="syz-executor526" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
==================================================================
BUG: KASAN: slab-out-of-bounds in __ext4_check_dir_entry+0x2ef/0x340 fs/ext4/dir.c:86
Read of size 1 at addr ffff88808ef64001 by task syz-executor526/6320

CPU: 1 PID: 6320 Comm: syz-executor526 Not tainted 4.14.184-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1dc mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0xa9/0x2b9 mm/kasan/report.c:393
 __ext4_check_dir_entry+0x2ef/0x340 fs/ext4/dir.c:86
 ext4_readdir+0x819/0x27e0 fs/ext4/dir.c:240
 iterate_dir+0x1a0/0x5e0 fs/readdir.c:52
 SYSC_getdents fs/readdir.c:269 [inline]
 SyS_getdents+0x132/0x260 fs/readdir.c:250
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x440259
RSP: 002b:00007fff473dace8 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007fff473dacf0 RCX: 0000000000440259
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000006ca018 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 000000000000000f R11: 0000000000000246 R12: 0000000000401b40
R13: 0000000000401bd0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4655:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551
 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552
 getname_flags+0xc8/0x550 fs/namei.c:138
 getname fs/namei.c:209 [inline]
 user_path_create fs/namei.c:3732 [inline]
 SYSC_symlinkat fs/namei.c:4176 [inline]
 SyS_symlinkat+0xa2/0x1f0 fs/namei.c:4163
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 4655:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xaf/0x190 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kmem_cache_free+0x7c/0x2b0 mm/slab.c:3758
 putname+0xcd/0x110 fs/namei.c:259
 filename_create+0x1c1/0x3f0 fs/namei.c:3697
 user_path_create fs/namei.c:3732 [inline]
 SYSC_symlinkat fs/namei.c:4176 [inline]
 SyS_symlinkat+0xb4/0x1f0 fs/namei.c:4163
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff88808ef64200
 which belongs to the cache names_cache of size 4096
The buggy address is located 511 bytes to the left of
 4096-byte region [ffff88808ef64200, ffff88808ef65200)
The buggy address belongs to the page:
page:ffffea00023bd900 count:1 mapcount:0 mapping:ffff88808ef64200 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffff88808ef64200 0000000000000000 0000000100000001
raw: ffffea00023a9420 ffffea0002371920 ffff8880aa9dacc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808ef63f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808ef63f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808ef64000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff88808ef64080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808ef64100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================