==================================================================
BUG: KASA[  223.018977][ T4625] BUG: KASAN: slab-out-of-bounds in memcpy_from_iter lib/iov_iter.c:85 [inline]
BUG: KASA[  223.018977][ T4625] BUG: KASAN: slab-out-of-bounds in iterate_bvec include/linux/iov_iter.h:123 [inline]
BUG: KASA[  223.018977][ T4625] BUG: KASAN: slab-out-of-bounds in iterate_and_advance2 include/linux/iov_iter.h:306 [inline]
BUG: KASA[  223.018977][ T4625] BUG: KASAN: slab-out-of-bounds in iterate_and_advance include/linux/iov_iter.h:330 [inline]
BUG: KASA[  223.018977][ T4625] BUG: KASAN: slab-out-of-bounds in __copy_from_iter lib/iov_iter.c:261 [inline]
BUG: KASA[  223.018977][ T4625] BUG: KASAN: slab-out-of-bounds in copy_folio_from_iter_atomic+0xbbf/0x1a30 lib/iov_iter.c:491
Read of size 4096 at addr ffff88805ebfb000 by task kworker/u8:12/4625

CPU: 1 UID: 0 PID: 4625 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: loop5 loop_workfn
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 memcpy_from_iter lib/iov_iter.c:85 [inline]
 iterate_bvec include/linux/iov_iter.h:123 [inline]
 iterate_and_advance2 include/linux/iov_iter.h:306 [inline]
 iterate_and_advance include/linux/iov_iter.h:330 [inline]
 __copy_from_iter lib/iov_iter.c:261 [inline]
 copy_folio_from_iter_atomic+0xbbf/0x1a30 lib/iov_iter.c:491
 generic_perform_write+0x5a8/0x8b0 mm/filemap.c:4376
 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3414
 lo_rw_aio+0xc78/0xf30 include/linux/percpu-rwsem.h:-1
 do_req_filebacked drivers/block/loop.c:429 [inline]
 loop_handle_cmd drivers/block/loop.c:1921 [inline]
 loop_process_work+0x638/0x11d0 drivers/block/loop.c:1956
 process_one_work kernel/workqueue.c:3322 [inline]
 process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 7340:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4612 [inline]
 slab_alloc_node mm/slub.c:4945 [inline]
 kmem_cache_alloc_noprof+0x355/0x650 mm/slub.c:4959
 vm_area_alloc+0x24/0x140 mm/vma_init.c:32
 __install_special_mapping mm/mmap.c:1459 [inline]
 _install_special_mapping+0x2e/0x350 mm/mmap.c:1509
 map_vdso+0x1f9/0x6a0 arch/x86/entry/vdso/vma.c:191
 load_elf_binary+0x1d6c/0x2970 fs/binfmt_elf.c:1291
 search_binary_handler fs/exec.c:1694 [inline]
 exec_binprm fs/exec.c:1726 [inline]
 bprm_execve+0x926/0x14b0 fs/exec.c:1778
 do_execveat_common+0x4f4/0x670 fs/exec.c:1876
 __do_sys_execve fs/exec.c:1949 [inline]
 __se_sys_execve fs/exec.c:1943 [inline]
 __x64_sys_execve+0x97/0xc0 fs/exec.c:1943
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88805ebfb000
 which belongs to the cache vm_area_struct of size 256
The buggy address is located 0 bytes inside of
 allocated 256-byte region [ffff88805ebfb000, ffff88805ebfb100)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805ebfb280 pfn:0x5ebfb
memcg:ffff88805ebfbf01
flags: 0x80000000000200(workingset|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000200 ffff88801b6f5c80 ffff88801b6f6288 ffff88801b6f6288
raw: ffff88805ebfb280 00000008000c0002 00000000f5000000 ffff88805ebfbf01
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 7340, tgid 7340 (sed), ts 223009797260, free_ts 223001637609
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0x262a/0x26a0 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3294 [inline]
 allocate_slab+0x79/0x5e0 mm/slub.c:3408
 new_slab mm/slub.c:3454 [inline]
 refill_objects+0x2d8/0x350 mm/slub.c:7338
 refill_sheaf mm/slub.c:2832 [inline]
 __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4703
 alloc_from_pcs mm/slub.c:4801 [inline]
 slab_alloc_node mm/slub.c:4933 [inline]
 kmem_cache_alloc_noprof+0x452/0x650 mm/slub.c:4959
 vm_area_alloc+0x24/0x140 mm/vma_init.c:32
 __install_special_mapping mm/mmap.c:1459 [inline]
 _install_special_mapping+0x2e/0x350 mm/mmap.c:1509
 map_vdso+0x1cf/0x6a0 arch/x86/entry/vdso/vma.c:178
 load_elf_binary+0x1d6c/0x2970 fs/binfmt_elf.c:1291
 search_binary_handler fs/exec.c:1694 [inline]
 exec_binprm fs/exec.c:1726 [inline]
 bprm_execve+0x926/0x14b0 fs/exec.c:1778
 do_execveat_common+0x4f4/0x670 fs/exec.c:1876
 __do_sys_execve fs/exec.c:1949 [inline]
 __se_sys_execve fs/exec.c:1943 [inline]
 __x64_sys_execve+0x97/0xc0 fs/exec.c:1943
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 6578 tgid 6578 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x10e7/0x11c0 mm/page_alloc.c:2950
 lbmLogShutdown fs/jfs/jfs_logmgr.c:1861 [inline]
 lmLogShutdown+0x44e/0x850 fs/jfs/jfs_logmgr.c:1681
 lmLogClose+0x28c/0x530 fs/jfs/jfs_logmgr.c:1457
 jfs_umount+0x2da/0x3b0 fs/jfs/jfs_umount.c:124
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x13d/0x2d0 fs/super.c:647
 kill_block_super+0x44/0x90 fs/super.c:1665
 deactivate_locked_super+0xbc/0x130 fs/super.c:477
 cleanup_mnt+0x3d3/0x460 fs/namespace.c:1317
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88805ebfb000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805ebfb080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805ebfb100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                   ^
 ffff88805ebfb180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805ebfb200: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
==================================================================