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BUG: KASAN: use-after-free in memcpy_from_iter lib/iov_iter.c:380 [inline]
BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0x93b/0x1310 lib/iov_iter.c:581
Read of size 4096 at addr ffff888028149000 by task kworker/u4:2/41

CPU: 0 PID: 41 Comm: kworker/u4:2 Not tainted 6.5.0-rc1-syzkaller-00033-geb26cbb1a754 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Workqueue: loop2 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x175/0x1b0 mm/kasan/report.c:588
 kasan_check_range+0x27e/0x290 mm/kasan/generic.c:187
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 memcpy_from_iter lib/iov_iter.c:380 [inline]
 copy_page_from_iter_atomic+0x93b/0x1310 lib/iov_iter.c:581
 generic_perform_write+0x392/0x630 mm/filemap.c:3931
 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4044
 do_iter_write+0x84f/0xde0 fs/read_write.c:860
 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:1886 [inline]
 loop_process_work+0x144b/0x2220 drivers/block/loop.c:1921
 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2597
 worker_thread+0xa63/0x1210 kernel/workqueue.c:2748
 kthread+0x2b8/0x350 kernel/kthread.c:389
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000a05240 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28149
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea0000a849c8 ffffea0000b2ba48 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 5731, tgid 5730 (syz-executor.2), ts 191125369481, free_ts 191229742755
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x31e8/0x3370 mm/page_alloc.c:3221
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4477
 lbmLogInit fs/jfs/jfs_logmgr.c:1816 [inline]
 lmLogInit+0x37a/0x1c90 fs/jfs/jfs_logmgr.c:1270
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x556/0x1030 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0xf1/0x6a0 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x681/0xc50 fs/jfs/super.c:565
 mount_bdev+0x276/0x3b0 fs/super.c:1391
 legacy_get_tree+0xef/0x190 fs/fs_context.c:611
 vfs_get_tree+0x8c/0x270 fs/super.c:1519
 do_new_mount+0x28f/0xae0 fs/namespace.c:3335
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
 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+0x63/0xcd
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2348
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2443
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogShutdown+0x4fc/0x970 fs/jfs/jfs_logmgr.c:1684
 lmLogClose+0x297/0x530 fs/jfs/jfs_logmgr.c:1460
 jfs_umount+0x2ce/0x3a0 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x8a/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x134/0x340 fs/super.c:499
 kill_block_super+0x68/0xa0 fs/super.c:1417
 deactivate_locked_super+0xa4/0x110 fs/super.c:330
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1254
 task_work_run+0x24a/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888028148f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
 ffff888028148f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888028149000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888028149080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888028149100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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