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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:249 [inline]
BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0x8bc/0x1160 lib/iov_iter.c:481
Read of size 4096 at addr ffff8880235d0000 by task kworker/u32:3/46

CPU: 1 PID: 46 Comm: kworker/u32:3 Not tainted 6.10.0-rc5-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: loop1 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189
 __asan_memcpy+0x23/0x60 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:249 [inline]
 copy_page_from_iter_atomic+0x8bc/0x1160 lib/iov_iter.c:481
 generic_perform_write+0x2ee/0x620 mm/filemap.c:4023
 shmem_file_write_iter+0x114/0x140 mm/shmem.c:2919
 do_iter_readv_writev+0x504/0x780 fs/read_write.c:741
 vfs_iter_write+0x1eb/0x9c0 fs/read_write.c:895
 lo_write_bvec drivers/block/loop.c:246 [inline]
 lo_write_simple drivers/block/loop.c:267 [inline]
 do_req_filebacked drivers/block/loop.c:514 [inline]
 loop_handle_cmd drivers/block/loop.c:1930 [inline]
 loop_process_work+0x14dd/0x2000 drivers/block/loop.c:1965
 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x523 pfn:0x235d0
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 ffffea0001126888 ffffea000079a648 0000000000000000
raw: 0000000000000523 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 5981, tgid 5980 (syz-executor.1), ts 93918209009, free_ts 93988101554
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1468
 prep_new_page mm/page_alloc.c:1476 [inline]
 get_page_from_freelist+0x136a/0x2e50 mm/page_alloc.c:3420
 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4678
 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265
 lbmLogInit fs/jfs/jfs_logmgr.c:1816 [inline]
 lmLogInit+0x4e3/0x1a90 fs/jfs/jfs_logmgr.c:1270
 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline]
 lmLogOpen+0x7e1/0x1400 fs/jfs/jfs_logmgr.c:1069
 jfs_mount_rw+0x2ea/0x700 fs/jfs/jfs_mount.c:257
 jfs_fill_super+0x9d6/0xd20 fs/jfs/super.c:565
 mount_bdev+0x1e3/0x2d0 fs/super.c:1659
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8f/0x380 fs/super.c:1780
 do_new_mount fs/namespace.c:3352 [inline]
 path_mount+0x14e6/0x1f20 fs/namespace.c:3679
 do_mount fs/namespace.c:3692 [inline]
 __do_sys_mount fs/namespace.c:3898 [inline]
 __se_sys_mount fs/namespace.c:3875 [inline]
 __x64_sys_mount+0x297/0x320 fs/namespace.c:3875
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5229 tgid 5229 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1088 [inline]
 free_unref_page+0x64a/0xe40 mm/page_alloc.c:2583
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogShutdown+0x371/0x780 fs/jfs/jfs_logmgr.c:1684
 lmLogClose+0x57b/0x710 fs/jfs/jfs_logmgr.c:1460
 jfs_umount+0x2f0/0x440 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x88/0x1d0 fs/jfs/super.c:194
 generic_shutdown_super+0x159/0x3d0 fs/super.c:642
 kill_block_super+0x3b/0x90 fs/super.c:1676
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473
 deactivate_super+0xde/0x100 fs/super.c:506
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880235cff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880235cff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880235d0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8880235d0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8880235d0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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