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

write to 0xffff888107255a90 of 8 bytes by task 3299 on cpu 0:
 hlist_bl_add_head_rcu include/linux/rculist_bl.h:91 [inline]
 __d_rehash+0xa3/0x1d0 fs/dcache.c:2709
 __d_add+0x326/0x490 fs/dcache.c:2937
 d_splice_alias_ops+0xe3/0x370 fs/dcache.c:3286
 proc_sys_lookup+0x1ed/0x310 fs/proc/proc_sysctl.c:544
 lookup_open fs/namei.c:4481 [inline]
 open_last_lookups fs/namei.c:4608 [inline]
 path_openat+0xb8c/0x2000 fs/namei.c:4860
 do_file_open+0x16c/0x290 fs/namei.c:4892
 do_sys_openat2+0xa0/0x130 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1385
 x64_sys_call+0x1e39/0x3020 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888107255a90 of 8 bytes by task 3300 on cpu 1:
 hlist_bl_unhashed include/linux/list_bl.h:54 [inline]
 d_unhashed include/linux/dcache.h:396 [inline]
 __d_lookup+0xf8/0x340 fs/dcache.c:2620
 lookup_fast+0x5e/0x320 fs/namei.c:1878
 lookup_fast_for_open fs/namei.c:4545 [inline]
 open_last_lookups fs/namei.c:4579 [inline]
 path_openat+0x423/0x2000 fs/namei.c:4860
 do_file_open+0x16c/0x290 fs/namei.c:4892
 do_sys_openat2+0xa0/0x130 fs/open.c:1368
 do_sys_open fs/open.c:1374 [inline]
 __do_sys_openat fs/open.c:1390 [inline]
 __se_sys_openat fs/open.c:1385 [inline]
 __x64_sys_openat+0xf2/0x120 fs/open.c:1385
 x64_sys_call+0x1e39/0x3020 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x136/0x3c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888237ab75d8 -> 0xffff888105e5a9c8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 3300 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 netdevsim3 netdevsim0: renamed from eth0
8021q: adding VLAN 0 to HW filter on device netdevsim0
netdevsim netdevsim3 netdevsim1: renamed from eth1
8021q: adding VLAN 0 to HW filter on device netdevsim1
netdevsim netdevsim3 netdevsim2: renamed from eth2
8021q: adding VLAN 0 to HW filter on device netdevsim2
netdevsim netdevsim3 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