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BUG: KASAN: use-after-free in memcpy include/linux/fortify-string.h:191 [inline]
BUG: KASAN: use-after-free in memcpy_from_page include/linux/highmem.h:321 [inline]
BUG: KASAN: use-after-free in iov_iter_copy_from_user_atomic+0x975/0x1520 lib/iov_iter.c:1053
Read of size 4096 at addr ffff888067752000 by task loop2/12573

CPU: 3 PID: 12573 Comm: loop2 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436
 check_region_inline mm/kasan/generic.c:180 [inline]
 kasan_check_range+0x13d/0x180 mm/kasan/generic.c:186
 memcpy+0x20/0x60 mm/kasan/shadow.c:65
 memcpy include/linux/fortify-string.h:191 [inline]
 memcpy_from_page include/linux/highmem.h:321 [inline]
 iov_iter_copy_from_user_atomic+0x975/0x1520 lib/iov_iter.c:1053
 generic_perform_write+0x277/0x4f0 mm/filemap.c:3668
 __generic_file_write_iter+0x24e/0x610 mm/filemap.c:3789
 generic_file_write_iter+0xd7/0x220 mm/filemap.c:3821
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x46f/0x740 fs/read_write.c:740
 do_iter_write+0x188/0x670 fs/read_write.c:866
 vfs_iter_write+0x70/0xa0 fs/read_write.c:907
 lo_write_bvec+0x141/0x6c0 drivers/block/loop.c:285
 lo_write_simple drivers/block/loop.c:307 [inline]
 do_req_filebacked drivers/block/loop.c:630 [inline]
 loop_handle_cmd drivers/block/loop.c:2046 [inline]
 loop_queue_work+0xb70/0x1f40 drivers/block/loop.c:2064
 kthread_worker_fn+0x322/0xcf0 kernel/kthread.c:756
 kthread+0x3b1/0x4a0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

The buggy address belongs to the page:
page:ffffea00019dd480 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x67752
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff00000000000 ffffea00011f75c8 ffffea0001de6588 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 0xdc0(GFP_KERNEL|__GFP_ZERO), pid 12570, ts 346440335251, free_ts 346671652631
 prep_new_page mm/page_alloc.c:2358 [inline]
 get_page_from_freelist+0x1033/0x2b60 mm/page_alloc.c:3994
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5200
 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272
 lbmLogInit fs/jfs/jfs_logmgr.c:1823 [inline]
 lmLogInit+0x358/0x1790 fs/jfs/jfs_logmgr.c:1278
 open_inline_log fs/jfs/jfs_logmgr.c:1183 [inline]
 lmLogOpen+0x7c8/0x13e0 fs/jfs/jfs_logmgr.c:1077
 jfs_mount_rw+0x321/0x5d0 fs/jfs/jfs_mount.c:260
 jfs_fill_super+0x871/0xc80 fs/jfs/super.c:570
 mount_bdev+0x34d/0x410 fs/super.c:1368
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1498
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x132a/0x1fa0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount fs/namespace.c:3433 [inline]
 __ia32_sys_mount+0x27e/0x300 fs/namespace.c:3433
 do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline]
 __do_fast_syscall_32+0x67/0xe0 arch/x86/entry/common.c:143
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:168
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1298 [inline]
 free_pcp_prepare+0x223/0x300 mm/page_alloc.c:1342
 free_unref_page_prepare mm/page_alloc.c:3250 [inline]
 free_unref_page+0x12/0x1d0 mm/page_alloc.c:3298
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1871 [inline]
 lmLogShutdown+0x33d/0x600 fs/jfs/jfs_logmgr.c:1691
 lmLogClose+0x55f/0x700 fs/jfs/jfs_logmgr.c:1467
 jfs_umount+0x2d3/0x3f0 fs/jfs/jfs_umount.c:116
 jfs_put_super+0x81/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x14c/0x370 fs/super.c:465
 kill_block_super+0x97/0xf0 fs/super.c:1395
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 deactivate_super+0xad/0xd0 fs/super.c:366
 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1136
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x272/0x280 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301
 __do_fast_syscall_32+0x74/0xe0 arch/x86/entry/common.c:146
 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:168

Memory state around the buggy address:
 ffff888067751f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888067751f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888067752000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff888067752080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888067752100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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