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BUG: KASAN: use-after-free in copy_page_from_iter_atomic+0xa9b/0x1060 lib/iov_iter.c:821
Read of size 4096 at addr ffff888028ec6000 by task kworker/u4:6/20479

CPU: 1 PID: 20479 Comm: kworker/u4:6 Not tainted 6.2.0-rc6-syzkaller-00003-g22b8077d0fce #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Workqueue: loop0 loop_workfn
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:306 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:417
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
 check_region_inline mm/kasan/generic.c:183 [inline]
 kasan_check_range+0x141/0x190 mm/kasan/generic.c:189
 memcpy+0x24/0x60 mm/kasan/shadow.c:65
 copy_page_from_iter_atomic+0xa9b/0x1060 lib/iov_iter.c:821
 generic_perform_write+0x2ca/0x570 mm/filemap.c:3780
 __generic_file_write_iter+0x2ae/0x500 mm/filemap.c:3900
 generic_file_write_iter+0xe3/0x350 mm/filemap.c:3932
 call_write_iter include/linux/fs.h:2189 [inline]
 do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735
 do_iter_write+0x182/0x700 fs/read_write.c:861
 vfs_iter_write+0x74/0xa0 fs/read_write.c:902
 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:1873 [inline]
 loop_process_work+0xdad/0x2070 drivers/block/loop.c:1908
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x669/0x1090 kernel/workqueue.c:2436
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0000a3b180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x28ec6
memcg:ffff888077974202
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff888077974202
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x102dc2(GFP_HIGHUSER|__GFP_NOWARN|__GFP_ZERO), pid 26928, tgid 26928 (syz-executor.0), ts 1799937895668, free_ts 1799896641863
 prep_new_page mm/page_alloc.c:2531 [inline]
 get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283
 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286
 vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
 __vmalloc_area_node mm/vmalloc.c:3057 [inline]
 __vmalloc_node_range+0x978/0x13c0 mm/vmalloc.c:3227
 alloc_thread_stack_node kernel/fork.c:311 [inline]
 dup_task_struct kernel/fork.c:987 [inline]
 copy_process+0x12d2/0x7520 kernel/fork.c:2097
 kernel_clone+0xeb/0x990 kernel/fork.c:2681
 __do_sys_clone+0xba/0x100 kernel/fork.c:2822
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 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:1446 [inline]
 free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496
 free_unref_page_prepare mm/page_alloc.c:3369 [inline]
 free_unref_page+0x1d/0x490 mm/page_alloc.c:3464
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline]
 lmLogShutdown+0x341/0x600 fs/jfs/jfs_logmgr.c:1684
 lmLogClose+0x55f/0x6f0 fs/jfs/jfs_logmgr.c:1460
 jfs_umount+0x2ef/0x410 fs/jfs/jfs_umount.c:114
 jfs_put_super+0x85/0x1a0 fs/jfs/super.c:194
 generic_shutdown_super+0x158/0x410 fs/super.c:492
 kill_block_super+0x9b/0xf0 fs/super.c:1386
 deactivate_locked_super+0x98/0x160 fs/super.c:332
 deactivate_super+0xb1/0xd0 fs/super.c:363
 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888028ec5f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888028ec5f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff888028ec6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                   ^
 ffff888028ec6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888028ec6100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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