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BUG: KASAN: use-after-free in do_shrink_slab+0xbd4/0xcb0 mm/vmscan.c:456
Read of size 8 at addr ffff8801d4c44ad8 by task syz-executor0/24477

CPU: 1 PID: 24477 Comm: syz-executor0 Not tainted 4.18.0+ #199
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+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 do_shrink_slab+0xbd4/0xcb0 mm/vmscan.c:456
 shrink_slab_memcg mm/vmscan.c:600 [inline]
 shrink_slab+0x7b7/0x990 mm/vmscan.c:673
 shrink_node+0x429/0x16a0 mm/vmscan.c:2734
 shrink_zones mm/vmscan.c:2963 [inline]
 do_try_to_free_pages+0x3e7/0x1290 mm/vmscan.c:3025
 try_to_free_mem_cgroup_pages+0x49d/0xc90 mm/vmscan.c:3323
 memory_high_write+0x283/0x310 mm/memcontrol.c:5399
 cgroup_file_write+0x31f/0x840 kernel/cgroup/cgroup.c:3447
 kernfs_fop_write+0x2ba/0x480 fs/kernfs/file.c:316
 do_loop_readv_writev fs/read_write.c:703 [inline]
 do_iter_write+0x491/0x5f0 fs/read_write.c:961
 vfs_writev+0x1f1/0x360 fs/read_write.c:1004
 do_writev+0x11a/0x310 fs/read_write.c:1039
 __do_sys_writev fs/read_write.c:1112 [inline]
 __se_sys_writev fs/read_write.c:1109 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457089
Code: fd b4 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 b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7be2f7fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f7be2f806d4 RCX: 0000000000457089
RDX: 0000000000000001 RSI: 0000000020000700 RDI: 0000000000000004
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d77f0 R14: 00000000004c834e R15: 0000000000000000

Allocated by task 21517:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kmem_cache_alloc_trace+0x152/0x780 mm/slab.c:3620
 kmalloc include/linux/slab.h:513 [inline]
 kzalloc include/linux/slab.h:707 [inline]
 __do_execve_file.isra.35+0x444/0x25e0 fs/exec.c:1742
 do_execveat_common fs/exec.c:1865 [inline]
 do_execve fs/exec.c:1882 [inline]
 __do_sys_execve fs/exec.c:1963 [inline]
 __se_sys_execve fs/exec.c:1958 [inline]
 __x64_sys_execve+0x8f/0xc0 fs/exec.c:1958
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 21517:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xd9/0x260 mm/slab.c:3813
 free_bprm+0x1b1/0x210 fs/exec.c:1428
 __do_execve_file.isra.35+0x1d35/0x25e0 fs/exec.c:1829
 do_execveat_common fs/exec.c:1865 [inline]
 do_execve fs/exec.c:1882 [inline]
 __do_sys_execve fs/exec.c:1963 [inline]
 __se_sys_execve fs/exec.c:1958 [inline]
 __x64_sys_execve+0x8f/0xc0 fs/exec.c:1958
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801d4c44a80
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 88 bytes inside of
 256-byte region [ffff8801d4c44a80, ffff8801d4c44b80)
The buggy address belongs to the page:
page:ffffea0007531100 count:1 mapcount:0 mapping:ffff8801dac007c0 index:0xffff8801d4c44bc0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea000713ea08 ffffea0006b9bf88 ffff8801dac007c0
raw: ffff8801d4c44bc0 ffff8801d4c44080 0000000100000009 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d4c44980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d4c44a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8801d4c44a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8801d4c44b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d4c44b80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
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