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BUG: KASAN: use-after-free in memcpy_from_iter lib/iov_iter.c:73 [inline]
BUG: KASAN: use-after-free in iterate_bvec include/linux/iov_iter.h:122 [inline]
BUG: KASAN: use-after-free in iterate_and_advance2 include/linux/iov_iter.h:249 [inline]
BUG: KASAN: use-after-free in iterate_and_advance include/linux/iov_iter.h:271 [inline]
BUG: KASAN: use-after-free in __copy_from_iter lib/iov_iter.c:268 [inline]
BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0x9b4/0x1e80 lib/iov_iter.c:500
Read of size 4096 at addr ffff888025f19000 by task kworker/u4:6/2796

CPU: 0 PID: 2796 Comm: kworker/u4:6 Not tainted 6.7.0-rc2-syzkaller-00242-g090472ed9c92 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Workqueue: loop5 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+0x142/0x170 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:73 [inline]
 iterate_bvec include/linux/iov_iter.h:122 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:249 [inline]
 iterate_and_advance include/linux/iov_iter.h:271 [inline]
 __copy_from_iter lib/iov_iter.c:268 [inline]
 copy_page_from_iter_atomic+0x9b4/0x1e80 lib/iov_iter.c:500
 generic_perform_write+0x392/0x630 mm/filemap.c:3926
 shmem_file_write_iter+0xfc/0x120 mm/shmem.c:2878
 do_iter_readv_writev+0x330/0x4a0
 do_iter_write+0x1f6/0x8d0 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:1915 [inline]
 loop_process_work+0x14c5/0x22a0 drivers/block/loop.c:1950
 process_one_work kernel/workqueue.c:2630 [inline]
 process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2703
 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2784
 kthread+0x2d3/0x370 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000097c640 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25f19
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 ffffea00007b66c8 ffffea00007a0908 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 11822, tgid 11821 (syz-executor.5), ts 704339588834, free_ts 704694999720
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1537
 prep_new_page mm/page_alloc.c:1544 [inline]
 get_page_from_freelist+0x33ea/0x3570 mm/page_alloc.c:3312
 __alloc_pages+0x255/0x680 mm/page_alloc.c:4568
 alloc_pages_mpol+0x3de/0x640 mm/mempolicy.c:2133
 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+0x573/0x1050 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+0x237/0x300 fs/super.c:1650
 legacy_get_tree+0xef/0x190 fs/fs_context.c:662
 vfs_get_tree+0x8c/0x2a0 fs/super.c:1771
 do_new_mount+0x28f/0xae0 fs/namespace.c:3337
 do_mount fs/namespace.c:3677 [inline]
 __do_sys_mount fs/namespace.c:3886 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3863
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1137 [inline]
 free_unref_page_prepare+0x931/0xa60 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 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+0x13a/0x2c0 fs/super.c:696
 kill_block_super+0x44/0x90 fs/super.c:1667
 deactivate_locked_super+0xc1/0x130 fs/super.c:484
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256
 task_work_run+0x24a/0x300 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x150 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x69/0x2a0 kernel/entry/common.c:296
 do_syscall_64+0x52/0x110 arch/x86/entry/common.c:88
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Memory state around the buggy address:
 ffff888025f18f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888025f18f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888025f19000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888025f19080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888025f19100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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