==================================================================
BUG: KCSAN: data-race in filemap_read / filemap_read

write to 0xffff88815576fc90 of 8 bytes by task 652 on cpu 0:
 filemap_read+0x615/0x690 mm/filemap.c:2670
 generic_file_read_iter+0x78/0x340 mm/filemap.c:2782
 ext4_file_read_iter+0x1d8/0x2a0
 do_iter_readv_writev+0x339/0x3e0
 vfs_iter_read+0x172/0x3a0 fs/read_write.c:830
 lo_read_simple drivers/block/loop.c:286 [inline]
 do_req_filebacked drivers/block/loop.c:496 [inline]
 loop_handle_cmd drivers/block/loop.c:1907 [inline]
 loop_process_work+0x7bc/0x1110 drivers/block/loop.c:1942
 loop_workfn+0x31/0x40 drivers/block/loop.c:1966
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

read to 0xffff88815576fc90 of 8 bytes by task 27 on cpu 1:
 filemap_read+0x89/0x690 mm/filemap.c:2577
 generic_file_read_iter+0x78/0x340 mm/filemap.c:2782
 ext4_file_read_iter+0x1d8/0x2a0
 do_iter_readv_writev+0x339/0x3e0
 vfs_iter_read+0x172/0x3a0 fs/read_write.c:830
 lo_read_simple drivers/block/loop.c:286 [inline]
 do_req_filebacked drivers/block/loop.c:496 [inline]
 loop_handle_cmd drivers/block/loop.c:1907 [inline]
 loop_process_work+0x7bc/0x1110 drivers/block/loop.c:1942
 loop_workfn+0x31/0x40 drivers/block/loop.c:1966
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
 worker_thread+0x526/0x730 kernel/workqueue.c:3416
 kthread+0x1d1/0x210 kernel/kthread.c:388
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

value changed: 0x0000000000037005 -> 0x0000000000043005

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 27 Comm: kworker/u8:1 Not tainted 6.8.0-syzkaller-13236-g5e74df2f8f15 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: loop6 loop_workfn
==================================================================
netdevsim netdevsim1 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim1 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim1 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 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
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): Released all slaves
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 promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed