syzbot

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BUG: KCSAN: data-race in __d_lookup_rcu / shrink_dentry_list

read-write to 0xffff888109f3db40 of 4 bytes by task 3099 on cpu 1:
 d_shrink_del fs/dcache.c:448 [inline]
 shrink_dentry_list+0x169/0x380 fs/dcache.c:1197
 prune_dcache_sb+0x81/0xb0 fs/dcache.c:1282
 super_cache_scan+0x26c/0x310 fs/super.c:104
 do_shrink_slab+0x2a0/0x640 mm/vmscan.c:911
 shrink_slab_memcg mm/vmscan.c:981 [inline]
 shrink_slab+0x2d6/0x650 mm/vmscan.c:1061
 shrink_node_memcgs mm/vmscan.c:6458 [inline]
 shrink_node+0xadf/0x1500 mm/vmscan.c:6491
 shrink_zones mm/vmscan.c:6726 [inline]
 do_try_to_free_pages+0x40d/0xc80 mm/vmscan.c:6788
 try_to_free_mem_cgroup_pages+0x1e2/0x480 mm/vmscan.c:7103
 reclaim_high+0xca/0x110 mm/memcontrol.c:2432
 mem_cgroup_handle_over_high+0x8c/0x1a0 mm/memcontrol.c:2617
 resume_user_mode_work include/linux/resume_user_mode.h:58 [inline]
 exit_to_user_mode_loop+0x9b/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888109f3db40 of 4 bytes by task 5354 on cpu 0:
 __d_lookup_rcu+0x42/0x290 fs/dcache.c:2361
 lookup_fast+0x8e/0x290 fs/namei.c:1625
 walk_component fs/namei.c:1994 [inline]
 link_path_walk+0x3f4/0x7e0 fs/namei.c:2325
 path_openat+0x19b/0x1d00 fs/namei.c:3787
 do_filp_open+0xf6/0x200 fs/namei.c:3818
 do_sys_openat2+0xb5/0x2a0 fs/open.c:1356
 do_sys_open fs/open.c:1372 [inline]
 __do_sys_openat fs/open.c:1388 [inline]
 __se_sys_openat fs/open.c:1383 [inline]
 __x64_sys_openat+0xf3/0x120 fs/open.c:1383
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x0028040c -> 0x0000800c

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5354 Comm: syz-executor.4 Not tainted 6.3.0-syzkaller-12728-g348551ddaf31 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
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