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BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0xef6/0x1b30 lib/iov_iter.c:969
Read of size 4096 at addr ffff88801c0ab000 by task kworker/u4:8/3728

CPU: 0 PID: 3728 Comm: kworker/u4:8 Not tainted 5.19.0-rc2-syzkaller-00241-g4b35035bcf80 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: loop4 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0xeb/0x495 mm/kasan/report.c:313
 print_report mm/kasan/report.c:429 [inline]
 kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
 memcpy+0x20/0x60 mm/kasan/shadow.c:65
 copy_page_from_iter_atomic+0xef6/0x1b30 lib/iov_iter.c:969
 generic_perform_write+0x2b8/0x560 mm/filemap.c:3778
 __generic_file_write_iter+0x2aa/0x4d0 mm/filemap.c:3898
 generic_file_write_iter+0xd7/0x220 mm/filemap.c:3930
 call_write_iter include/linux/fs.h:2058 [inline]
 do_iter_readv_writev+0x3d1/0x640 fs/read_write.c:742
 do_iter_write+0x182/0x700 fs/read_write.c:868
 vfs_iter_write+0x70/0xa0 fs/read_write.c:909
 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+0xd83/0x2050 drivers/block/loop.c:1894
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000702ac0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c0ab
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0000f69348 ffffea0000ec6fc8 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 1015, tgid 1014 (syz-executor.4), ts 1088668558680, free_ts 1088699891435
 prep_new_page mm/page_alloc.c:2456 [inline]
 get_page_from_freelist+0x1290/0x3b70 mm/page_alloc.c:4198
 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5426
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272
 lbmLogInit fs/jfs/jfs_logmgr.c:1816 [inline]
 lmLogInit+0x358/0x17a0 fs/jfs/jfs_logmgr.c:1270
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x7c8/0x13e0 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0x321/0x5d0 fs/jfs/jfs_mount.c:253
 jfs_fill_super+0x9bc/0xc70 fs/jfs/super.c:565
 mount_bdev+0x34d/0x410 fs/super.c:1367
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1497
 do_new_mount fs/namespace.c:3040 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount fs/namespace.c:3568 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 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+0x549/0xd20 mm/page_alloc.c:1421
 free_unref_page_prepare mm/page_alloc.c:3343 [inline]
 free_unref_page+0x19/0x6a0 mm/page_alloc.c:3438
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogShutdown+0x33d/0x600 fs/jfs/jfs_logmgr.c:1684
 lmLogClose+0x55f/0x700 fs/jfs/jfs_logmgr.c:1460
 jfs_umount+0x2d3/0x3f0 fs/jfs/jfs_umount.c:116
 jfs_put_super+0x81/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x14c/0x400 fs/super.c:462
 kill_block_super+0x97/0xf0 fs/super.c:1394
 deactivate_locked_super+0x94/0x160 fs/super.c:332
 deactivate_super+0xad/0xd0 fs/super.c:363
 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1186
 task_work_run+0xdd/0x1a0 kernel/task_work.c:177
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:169 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Memory state around the buggy address:
 ffff88801c0aaf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88801c0aaf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88801c0ab000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88801c0ab080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88801c0ab100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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