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BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0x6ca/0xeb0 lib/iov_iter.c:969
Read of size 4096 at addr ffff888025310000 by task kworker/u4:4/932

CPU: 0 PID: 932 Comm: kworker/u4:4 Not tainted 5.19.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023
Workqueue: loop3 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x167/0x217 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:313 [inline]
 print_report+0x139/0x670 mm/kasan/report.c:429
 kasan_report+0xfc/0x130 mm/kasan/report.c:491
 kasan_check_range+0x283/0x290 mm/kasan/generic.c:189
 memcpy+0x29/0x70 mm/kasan/shadow.c:65
 copy_page_from_iter_atomic+0x6ca/0xeb0 lib/iov_iter.c:969
 generic_perform_write+0x356/0x540 mm/filemap.c:3777
 __generic_file_write_iter+0x143/0x340 mm/filemap.c:3897
 generic_file_write_iter+0x9c/0x150 mm/filemap.c:3929
 do_iter_readv_writev+0x3ac/0x530
 do_iter_write+0x190/0x600 fs/read_write.c:868
 lo_write_bvec drivers/block/loop.c:249 [inline]
 lo_write_simple drivers/block/loop.c:271 [inline]
 do_req_filebacked drivers/block/loop.c:495 [inline]
 loop_handle_cmd drivers/block/loop.c:1859 [inline]
 loop_process_work+0x127b/0x1e60 drivers/block/loop.c:1894
 process_one_work+0x7b9/0xef0 kernel/workqueue.c:2289
 worker_thread+0x8c9/0xfd0 kernel/workqueue.c:2436
 kthread+0x238/0x2b0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000094c400 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25310
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea000055e708 ffffea0000729348 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x100dc0(GFP_USER|__GFP_ZERO), pid 7025, tgid 7010 (syz-executor.3), ts 330592334220, free_ts 330664205054
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1a1/0x1c0 mm/page_alloc.c:2449
 prep_new_page mm/page_alloc.c:2456 [inline]
 get_page_from_freelist+0x33ff/0x35a0 mm/page_alloc.c:4198
 __alloc_pages+0x291/0x750 mm/page_alloc.c:5426
 lbmLogInit fs/jfs/jfs_logmgr.c:1816 [inline]
 lmLogInit+0x366/0x1a50 fs/jfs/jfs_logmgr.c:1270
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x4ff/0xe30 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0x304/0x610 fs/jfs/jfs_mount.c:253
 jfs_remount+0x3cd/0x5f0 fs/jfs/super.c:454
 reconfigure_super+0x329/0x700 fs/super.c:905
 vfs_fsconfig_locked fs/fsopen.c:254 [inline]
 __do_sys_fsconfig fs/fsopen.c:439 [inline]
 __se_sys_fsconfig+0x8c8/0xb10 fs/fsopen.c:314
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1371 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0xf85/0x1130 mm/page_alloc.c:3343
 free_unref_page+0x99/0x2d0 mm/page_alloc.c:3438
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogShutdown+0x4f9/0x8c0 fs/jfs/jfs_logmgr.c:1684
 lmLogClose+0x38e/0x480 fs/jfs/jfs_logmgr.c:1460
 jfs_umount+0x25f/0x300 fs/jfs/jfs_umount.c:116
 jfs_put_super+0x73/0x140 fs/jfs/super.c:194
 generic_shutdown_super+0x10b/0x290 fs/super.c:462
 kill_block_super+0x79/0xc0 fs/super.c:1394
 deactivate_locked_super+0x75/0xd0 fs/super.c:332
 cleanup_mnt+0x395/0x440 fs/namespace.c:1186
 task_work_run+0xd4/0x160 kernel/task_work.c:177
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:169
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x61/0x290 kernel/entry/common.c:294
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Memory state around the buggy address:
 ffff88802530ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88802530ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888025310000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888025310080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888025310100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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