==================================================================
BUG: KCSAN: data-race in __d_rehash / fast_dput

write to 0xffff888100651010 of 8 bytes by task 3304 on cpu 1:
 hlist_bl_add_head_rcu include/linux/rculist_bl.h:91 [inline]
 __d_rehash+0xa4/0x1d0 fs/dcache.c:2714
 __d_add+0x326/0x490 fs/dcache.c:2942
 d_splice_alias_ops+0xe3/0x370 fs/dcache.c:3291
 proc_sys_lookup+0x1ed/0x310 fs/proc/proc_sysctl.c:544
 lookup_open+0x984/0x10d0 fs/namei.c:4528
 open_last_lookups fs/namei.c:4767 [inline]
 path_openat+0x415/0x10d0 fs/namei.c:4997
 do_file_open+0x16c/0x290 fs/namei.c:5029
 do_sys_openat2+0xa0/0x130 fs/open.c:1417
 do_sys_open fs/open.c:1423 [inline]
 __do_sys_openat fs/open.c:1439 [inline]
 __se_sys_openat fs/open.c:1434 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1434
 x64_sys_call+0x1f72/0x2550 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888100651010 of 8 bytes by task 3303 on cpu 0:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:396 [inline]
 retain_dentry fs/dcache.c:872 [inline]
 fast_dput+0x64/0x300 fs/dcache.c:971
 dput+0x1f/0x50 fs/dcache.c:1040
 __fput+0x43e/0x630 fs/file_table.c:520
 fput_close_sync+0xad/0x190 fs/file_table.c:617
 __do_sys_close fs/open.c:1560 [inline]
 __se_sys_close fs/open.c:1545 [inline]
 __x64_sys_close+0x55/0xf0 fs/open.c:1545
 x64_sys_call+0x812/0x2550 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x112/0x360 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff8882377b45c0 -> 0xffff888105cac788

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 3303 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(lazy) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
==================================================================
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered disabled state
bridge_slave_0: entered allmulticast mode
bridge_slave_0: entered promiscuous mode
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_1: entered allmulticast mode
bridge_slave_1: entered promiscuous mode
bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
team0: Port device team_slave_0 added
team0: Port device team_slave_1 added
batman_adv: batadv0: Adding interface: batadv_slave_0
batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
batman_adv: batadv0: Adding interface: batadv_slave_1
batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1532 would solve the problem.
batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
hsr_slave_0: entered promiscuous mode
hsr_slave_1: entered promiscuous mode
debugfs: 'hsr0' already exists in 'hsr'
Cannot create hsr debugfs directory
netdevsim netdevsim1 netdevsim0: renamed from eth0
8021q: adding VLAN 0 to HW filter on device netdevsim0
netdevsim netdevsim1 netdevsim1: renamed from eth1
8021q: adding VLAN 0 to HW filter on device netdevsim1
netdevsim netdevsim1 netdevsim2: renamed from eth2
8021q: adding VLAN 0 to HW filter on device netdevsim2
netdevsim netdevsim1 netdevsim3: renamed from eth3
8021q: adding VLAN 0 to HW filter on device netdevsim3
8021q: adding VLAN 0 to HW filter on device bond0
8021q: adding VLAN 0 to HW filter on device team0
8021q: adding VLAN 0 to HW filter on device batadv0
veth0_vlan: entered promiscuous mode
veth1_vlan: entered promiscuous mode
veth0_macvtap: entered promiscuous mode
veth1_macvtap: entered promiscuous mode
batman_adv: batadv0: Interface activated: batadv_slave_0
batman_adv: batadv0: Interface activated: batadv_slave_1