================================================================== BUG: KCSAN: data-race in rwsem_down_write_slowpath / rwsem_down_write_slowpath write to 0xffffc90001377158 of 1 bytes by task 16989 on cpu 0: rwsem_try_write_lock kernel/locking/rwsem.c:676 [inline] rwsem_down_write_slowpath+0x3eb/0xab0 kernel/locking/rwsem.c:1189 __down_write_common kernel/locking/rwsem.c:1347 [inline] __down_write kernel/locking/rwsem.c:1356 [inline] down_write+0xab/0xc0 kernel/locking/rwsem.c:1632 kernfs_activate+0x50/0x220 fs/kernfs/dir.c:1462 kernfs_add_one+0x208/0x290 fs/kernfs/dir.c:868 __kernfs_create_file+0x145/0x180 fs/kernfs/file.c:1079 sysfs_add_file_mode_ns+0x132/0x1b0 fs/sysfs/file.c:316 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x43e/0x9e0 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:229 [inline] sysfs_create_groups+0x3f/0xf0 fs/sysfs/group.c:255 create_dir lib/kobject.c:78 [inline] kobject_add_internal+0x49d/0x770 lib/kobject.c:240 kobject_add_varg lib/kobject.c:374 [inline] kobject_init_and_add+0x13c/0x1e0 lib/kobject.c:457 ext4_register_sysfs+0xa5/0x270 fs/ext4/sysfs.c:617 __ext4_fill_super fs/ext4/super.c:5743 [inline] ext4_fill_super+0x3696/0x3760 fs/ext4/super.c:5828 get_tree_bdev_flags+0x291/0x300 fs/super.c:1634 get_tree_bdev+0x1f/0x30 fs/super.c:1657 ext4_get_tree+0x1c/0x30 fs/ext4/super.c:5860 vfs_get_tree+0x57/0x1d0 fs/super.c:1694 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3765 [inline] do_new_mount+0x288/0x8d0 fs/namespace.c:3841 path_mount+0x4ad/0xb90 fs/namespace.c:4161 do_mount fs/namespace.c:4174 [inline] __do_sys_mount fs/namespace.c:4390 [inline] __se_sys_mount+0x28c/0x2e0 fs/namespace.c:4367 __x64_sys_mount+0x67/0x80 fs/namespace.c:4367 x64_sys_call+0x2d61/0x3020 arch/x86/include/generated/asm/syscalls_64.h:166 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 0xffffc90001377158 of 1 bytes by task 16898 on cpu 1: rwsem_down_write_slowpath+0x462/0xab0 kernel/locking/rwsem.c:1207 __down_write_common kernel/locking/rwsem.c:1347 [inline] __down_write kernel/locking/rwsem.c:1356 [inline] down_write+0xab/0xc0 kernel/locking/rwsem.c:1632 kernfs_add_one+0x5a/0x290 fs/kernfs/dir.c:825 __kernfs_create_file+0x145/0x180 fs/kernfs/file.c:1079 sysfs_add_file_mode_ns+0x132/0x1b0 fs/sysfs/file.c:316 create_files fs/sysfs/group.c:82 [inline] internal_create_group+0x43e/0x9e0 fs/sysfs/group.c:189 internal_create_groups fs/sysfs/group.c:229 [inline] sysfs_create_groups+0x3f/0xf0 fs/sysfs/group.c:255 device_add_groups drivers/base/core.c:2907 [inline] device_add_attrs+0x64/0x3f0 drivers/base/core.c:2971 device_add+0x37a/0x790 drivers/base/core.c:3711 netdev_register_kobject+0x108/0x220 net/core/net-sysfs.c:2337 register_netdevice+0xaf7/0x11a0 net/core/dev.c:11440 veth_newlink+0x4a5/0x780 drivers/net/veth.c:1892 rtnl_newlink_create+0x1e7/0x650 net/core/rtnetlink.c:3913 __rtnl_newlink net/core/rtnetlink.c:4044 [inline] rtnl_newlink+0x1181/0x1400 net/core/rtnetlink.c:4159 rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x11e/0x220 net/netlink/af_netlink.c:2556 rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7103 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x5a7/0x680 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x5be/0x6f0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x411/0x470 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0x76/0x90 net/socket.c:2255 x64_sys_call+0x2d35/0x3020 arch/x86/include/generated/asm/syscalls_64.h:45 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: 0x00 -> 0x01 Reported by Kernel Concurrency Sanitizer on: CPU: 1 UID: 0 PID: 16898 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT(lazy) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 ================================================================== hsr_slave_0: entered promiscuous mode hsr_slave_1: entered promiscuous mode debugfs: 'hsr0' already exists in 'hsr' Cannot create hsr debugfs directory netdevsim netdevsim9 netdevsim0: renamed from eth0 8021q: adding VLAN 0 to HW filter on device netdevsim0 netdevsim netdevsim9 netdevsim1: renamed from eth1 8021q: adding VLAN 0 to HW filter on device netdevsim1 netdevsim netdevsim9 netdevsim2: renamed from eth2 8021q: adding VLAN 0 to HW filter on device netdevsim2 netdevsim netdevsim9 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