================================================================== BUG: KCSAN: data-race in atime_needs_update / touch_atime write to 0xffff88811cbf69a0 of 4 bytes by task 321 on cpu 1: inode_set_atime_to_ts include/linux/fs.h:1624 [inline] inode_update_timestamps fs/inode.c:2129 [inline] generic_update_time fs/inode.c:2151 [inline] inode_update_time fs/inode.c:2171 [inline] touch_atime+0x1e8/0x340 fs/inode.c:2243 file_accessed include/linux/fs.h:2256 [inline] shmem_file_read_iter+0x477/0x540 mm/shmem.c:3493 lo_rw_aio+0x67d/0x730 drivers/block/loop.c:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1947 [inline] loop_process_work+0x56c/0xac0 drivers/block/loop.c:1982 loop_rootcg_workfn+0x22/0x30 drivers/block/loop.c:2013 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0x4cd/0x9d0 kernel/workqueue.c:3340 worker_thread+0x6bc/0x8b0 kernel/workqueue.c:3421 kthread+0x488/0x510 kernel/kthread.c:463 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 read to 0xffff88811cbf69a0 of 4 bytes by task 49 on cpu 0: atime_needs_update+0x25f/0x3e0 fs/inode.c:-1 touch_atime+0x4a/0x340 fs/inode.c:2226 file_accessed include/linux/fs.h:2256 [inline] shmem_file_read_iter+0x477/0x540 mm/shmem.c:3493 lo_rw_aio+0x67d/0x730 drivers/block/loop.c:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1947 [inline] loop_process_work+0x56c/0xac0 drivers/block/loop.c:1982 loop_workfn+0x31/0x40 drivers/block/loop.c:2006 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0x4cd/0x9d0 kernel/workqueue.c:3340 worker_thread+0x6bc/0x8b0 kernel/workqueue.c:3421 kthread+0x488/0x510 kernel/kthread.c:463 ret_from_fork+0x148/0x280 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 value changed: 0x3ac29ac2 -> 0x3b5b3142 Reported by Kernel Concurrency Sanitizer on: CPU: 0 UID: 0 PID: 49 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: loop1 loop_workfn ================================================================== netdevsim netdevsim0 netdevsim3 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim2 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim1 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim0 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 bridge_slave_1: left allmulticast mode bridge_slave_1: left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state bond5 (unregistering): (slave ip6gretap1): Releasing active interface bridge2 (unregistering): left allmulticast mode team0: Port device bond0 removed bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): left allmulticast mode bond2 (unregistering): left promiscuous mode team0: Port device macvlan2 removed bond2 (unregistering): Released all slaves bond3 (unregistering): Released all slaves bond4 (unregistering): (slave vlan1): Releasing active interface bond4 (unregistering): Released all slaves bond5 (unregistering): Released all slaves bond6 (unregistering): Released all slaves tipc: Left network mode batadv0: left promiscuous mode macvlan1: left promiscuous mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 veth1_macvtap: left promiscuous mode veth0_macvtap: left promiscuous mode veth1_vlan: left allmulticast mode veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed netdevsim netdevsim1 netdevsim3 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim1 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim2 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim1 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim1 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim1 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim1 netdevsim0 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0 netdevsim netdevsim1 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 bridge_slave_1: left allmulticast mode bridge_slave_1: left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state bond6 (unregistering): (slave ip6gretap1): Releasing active interface bond2 (unregistering): (slave vti0): Releasing backup interface vti0 (unregistering): left allmulticast mode bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): left allmulticast mode bond2 (unregistering): Released all slaves bond3 (unregistering): Released all slaves bond4 (unregistering): Released all slaves bond5 (unregistering): Released all slaves bond6 (unregistering): Released all slaves bond7 (unregistering): Released all slaves bond8 (unregistering): Released all slaves bond9 (unregistering): Released all slaves bond5 (unregistering): (slave ip6gretap1): Releasing active interface bond5 (unregistering): (slave ip6gretap1): the permanent HWaddr of slave - f6:5e:4a:30:56:4b - is still in use by bond - set the HWaddr of slave to a different address to avoid conflicts bond5 (unregistering): (slave vlan2): making interface the new active one bond2 (unregistering): (slave vti0): Releasing backup interface bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): Released all slaves bond3 (unregistering): Released all slaves bond4 (unregistering): Released all slaves bond5 (unregistering): (slave vlan2): Releasing active interface bond5 (unregistering): Released all slaves bond6 (unregistering): Released all slaves bond1 (unregistering): (slave vti0): Releasing backup interface vti0 (unregistering): left promiscuous mode batman_adv: batadv0: Removing interface: gretap1 bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): Released all slaves bond3 (unregistering): Released all slaves bond4 (unregistering): Released all slaves tipc: Left network mode tipc: Left network mode tipc: Left network mode batadv0: left promiscuous mode macvlan1: left promiscuous mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_1 hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_1 batman_adv: batadv0: Removing interface: dummy0 hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batadv0: mtu less than device minimum batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Forced to purge local tt entries to fit new maximum fragment MTU (0) batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 batman_adv: batadv0: Interface deactivated: dummy0 batman_adv: batadv0: Removing interface: dummy0 veth1_macvtap: left promiscuous mode veth0_macvtap: left promiscuous mode veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed