syzbot

==================================================================
BUG: KCSAN: data-race in __dput_to_list / link_path_walk

read-write to 0xffff88810a9b7900 of 4 bytes by task 17810 on cpu 1:
 d_shrink_add fs/dcache.c:456 [inline]
 __dput_to_list+0x1eb/0x240 fs/dcache.c:928
 shrink_dentry_list+0x196/0x380 fs/dcache.c:1200
 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:853
 shrink_slab_memcg mm/vmscan.c:941 [inline]
 shrink_slab+0x2fe/0x520 mm/vmscan.c:1001
 shrink_node_memcgs mm/vmscan.c:6439 [inline]
 shrink_node+0xaf5/0x14f0 mm/vmscan.c:6473
 shrink_zones mm/vmscan.c:6711 [inline]
 do_try_to_free_pages+0x40d/0xc80 mm/vmscan.c:6773
 try_to_free_mem_cgroup_pages+0x1e2/0x480 mm/vmscan.c:7088
 reclaim_high+0xca/0x110 mm/memcontrol.c:2403
 mem_cgroup_handle_over_high+0x8c/0x1a0 mm/memcontrol.c:2588
 resume_user_mode_work include/linux/resume_user_mode.h:58 [inline]
 exit_to_user_mode_loop+0x99/0xe0 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0x6a/0xa0 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88810a9b7900 of 4 bytes by task 17812 on cpu 0:
 link_path_walk+0x32f/0x7e0 fs/namei.c:2283
 path_lookupat+0x72/0x2a0 fs/namei.c:2474
 filename_lookup+0x126/0x300 fs/namei.c:2504
 user_path_at_empty+0x42/0x110 fs/namei.c:2877
 user_path_at include/linux/namei.h:57 [inline]
 path_setxattr+0x60/0x1a0 fs/xattr.c:646
 __do_sys_setxattr fs/xattr.c:667 [inline]
 __se_sys_setxattr fs/xattr.c:663 [inline]
 __x64_sys_setxattr+0x6d/0x80 fs/xattr.c:663
 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: 0x00200000 -> 0x00008000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17812 Comm: syz-executor.0 Not tainted 6.3.0-rc2-syzkaller-00006-gfc89d7fb499b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
==================================================================