================================================================== 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:123 [inline] BUG: KASAN: use-after-free in iterate_and_advance2 include/linux/iov_iter.h:306 [inline] BUG: KASAN: use-after-free in iterate_and_advance include/linux/iov_iter.h:330 [inline] BUG: KASAN: use-after-free in __copy_from_iter lib/iov_iter.c:249 [inline] BUG: KASAN: use-after-free in copy_folio_from_iter_atomic+0xb17/0x1910 lib/iov_iter.c:479 Read of size 4096 at addr ffff888058e52000 by task kworker/u8:46/7236 CPU: 0 UID: 0 PID: 7236 Comm: kworker/u8:46 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: loop0 loop_workfn Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105 memcpy_from_iter lib/iov_iter.c:73 [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:249 [inline] copy_folio_from_iter_atomic+0xb17/0x1910 lib/iov_iter.c:479 generic_perform_write+0x5df/0x900 mm/filemap.c:4194 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528 lo_rw_aio+0xcfa/0xfa0 include/linux/percpu-rwsem.h:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1913 [inline] loop_process_work+0x835/0xf90 drivers/block/loop.c:1948 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58e52 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea000170fdc8 ffffea00013987c8 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 13295, tgid 13292 (syz.0.2306), ts 285906437684, free_ts 285960767683 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline] alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507 lbmLogInit fs/jfs/jfs_logmgr.c:1816 [inline] lmLogInit+0x332/0x19e0 fs/jfs/jfs_logmgr.c:1270 open_inline_log fs/jfs/jfs_logmgr.c:1175 [inline] lmLogOpen+0x4e1/0xfb0 fs/jfs/jfs_logmgr.c:1069 jfs_mount_rw+0xe9/0x670 fs/jfs/jfs_mount.c:257 jfs_fill_super+0x754/0xd80 fs/jfs/super.c:532 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692 vfs_get_tree+0x92/0x2b0 fs/super.c:1752 do_new_mount+0x2a2/0xa30 fs/namespace.c:3810 do_mount fs/namespace.c:4138 [inline] __do_sys_mount fs/namespace.c:4349 [inline] __se_sys_mount+0x317/0x410 fs/namespace.c:4326 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 9286 tgid 9286 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895 lbmLogShutdown fs/jfs/jfs_logmgr.c:1864 [inline] lmLogShutdown+0x439/0x830 fs/jfs/jfs_logmgr.c:1684 lmLogClose+0x28a/0x520 fs/jfs/jfs_logmgr.c:1460 jfs_umount+0x2ef/0x3c0 fs/jfs/jfs_umount.c:114 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1723 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d1/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888058e51f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888058e51f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888058e52000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888058e52080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888058e52100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================