==================================================================
BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0x834/0xffc lib/iov_iter.c:978
Read of size 4096 at addr ffff0000e1435000 by task kworker/u4:13/4194

CPU: 1 PID: 4194 Comm: kworker/u4:13 Not tainted 5.15.169-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: loop0 loop_workfn
Call trace:
 dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 print_address_description+0x7c/0x3f0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0x174/0x1e4 mm/kasan/report.c:451
 kasan_check_range+0x274/0x2b4 mm/kasan/generic.c:189
 memcpy+0x90/0xe8 mm/kasan/shadow.c:65
 copy_page_from_iter_atomic+0x834/0xffc lib/iov_iter.c:978
 generic_perform_write+0x2d0/0x520 mm/filemap.c:3793
 __generic_file_write_iter+0x230/0x454 mm/filemap.c:3912
 generic_file_write_iter+0xb4/0x1b8 mm/filemap.c:3944
 do_iter_readv_writev+0x420/0x5f8
 do_iter_write+0x1b8/0x66c fs/read_write.c:855
 vfs_iter_write+0x88/0xac fs/read_write.c:896
 lo_write_bvec+0x394/0xb4c drivers/block/loop.c:316
 lo_write_simple drivers/block/loop.c:338 [inline]
 do_req_filebacked drivers/block/loop.c:656 [inline]
 loop_handle_cmd drivers/block/loop.c:2234 [inline]
 loop_process_work+0x1f24/0x2798 drivers/block/loop.c:2274
 loop_workfn+0x54/0x68 drivers/block/loop.c:2298
 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
 worker_thread+0x910/0x1034 kernel/workqueue.c:2457
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

The buggy address belongs to the page:
page:00000000c63b2625 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x121435
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 fffffc0003850d88 fffffc0003851248 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000e1434f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e1434f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff0000e1435000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff0000e1435080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff0000e1435100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready
bridge0: port 1(bridge_slave_0) entered blocking state
bridge0: port 1(bridge_slave_0) entered forwarding state
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready
bridge0: port 2(bridge_slave_1) entered blocking state
bridge0: port 2(bridge_slave_1) entered forwarding state
IPv6: ADDRCONF(NETDEV_CHANGE): bridge0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_macvtap: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): macsec0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_0: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready