===================================================== BUG: KMSAN: kernel-infoleak-after-free in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak-after-free in copy_to_user_iter lib/iov_iter.c:24 [inline] BUG: KMSAN: kernel-infoleak-after-free in iterate_ubuf include/linux/iov_iter.h:30 [inline] BUG: KMSAN: kernel-infoleak-after-free in iterate_and_advance2 include/linux/iov_iter.h:302 [inline] BUG: KMSAN: kernel-infoleak-after-free in iterate_and_advance include/linux/iov_iter.h:330 [inline] BUG: KMSAN: kernel-infoleak-after-free in _copy_to_iter+0xef3/0x33f0 lib/iov_iter.c:185 instrument_copy_to_user include/linux/instrumented.h:114 [inline] copy_to_user_iter lib/iov_iter.c:24 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0xef3/0x33f0 lib/iov_iter.c:185 copy_page_to_iter+0x482/0x910 lib/iov_iter.c:362 copy_folio_to_iter include/linux/uio.h:204 [inline] filemap_read+0x1cda/0x2300 mm/filemap.c:2763 blkdev_read_iter+0x89f/0xb00 block/fops.c:852 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x8ea/0xf90 fs/read_write.c:572 ksys_read fs/read_write.c:715 [inline] __do_sys_read fs/read_write.c:724 [inline] __se_sys_read fs/read_write.c:722 [inline] __x64_sys_read+0x1fb/0x4d0 fs/read_write.c:722 x64_sys_call+0x2f9c/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:1 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: memcpy_to_iter lib/iov_iter.c:65 [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_to_iter+0x130f/0x33f0 lib/iov_iter.c:185 copy_page_to_iter+0x482/0x910 lib/iov_iter.c:362 copy_folio_to_iter include/linux/uio.h:204 [inline] shmem_file_read_iter+0x904/0x1140 mm/shmem.c:3476 lo_rw_aio+0x1268/0x1590 drivers/block/loop.c:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1919 [inline] loop_process_work+0xe30/0x1ec0 drivers/block/loop.c:1954 loop_workfn+0x3e/0x60 drivers/block/loop.c:1978 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xb8e/0x1d80 kernel/workqueue.c:3319 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400 kthread+0xd59/0xf00 kernel/kthread.c:463 ret_from_fork+0x233/0x380 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Uninit was stored to memory at: 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+0x11f7/0x3c20 lib/iov_iter.c:479 generic_perform_write+0x8b1/0x1050 mm/filemap.c:4193 shmem_file_write_iter+0x2b7/0x2f0 mm/shmem.c:3528 lo_rw_aio+0x1268/0x1590 drivers/block/loop.c:-1 do_req_filebacked drivers/block/loop.c:-1 [inline] loop_handle_cmd drivers/block/loop.c:1919 [inline] loop_process_work+0xe30/0x1ec0 drivers/block/loop.c:1954 loop_workfn+0x3e/0x60 drivers/block/loop.c:1978 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xb8e/0x1d80 kernel/workqueue.c:3319 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400 kthread+0xd59/0xf00 kernel/kthread.c:463 ret_from_fork+0x233/0x380 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Uninit was stored to memory at: ntfs_write_bh+0x6ae/0xe90 fs/ntfs3/fsntfs.c:1430 mi_write+0xb4/0x2f0 fs/ntfs3/record.c:402 ni_write_inode+0xd95/0x1ca0 fs/ntfs3/frecord.c:3325 ntfs3_write_inode+0x94/0xb0 fs/ntfs3/inode.c:1036 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x88f/0x1190 fs/fs-writeback.c:1745 writeback_sb_inodes+0xac1/0x1cb0 fs/fs-writeback.c:1976 wb_writeback+0x4ce/0xc00 fs/fs-writeback.c:2156 wb_do_writeback fs/fs-writeback.c:2303 [inline] wb_workfn+0x397/0x1910 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xb8e/0x1d80 kernel/workqueue.c:3319 worker_thread+0xedf/0x1590 kernel/workqueue.c:3400 kthread+0xd59/0xf00 kernel/kthread.c:463 ret_from_fork+0x233/0x380 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Uninit was created at: slab_free_hook mm/slub.c:2348 [inline] slab_free mm/slub.c:4695 [inline] kmem_cache_free+0x2a1/0xec0 mm/slub.c:4797 putname fs/namei.c:297 [inline] kern_path+0x2fe/0x3b0 fs/namei.c:2818 ovl_mount_dir_noesc fs/overlayfs/params.c:239 [inline] ovl_mount_dir fs/overlayfs/params.c:270 [inline] ovl_kern_path fs/overlayfs/params.c:387 [inline] ovl_parse_layer fs/overlayfs/params.c:436 [inline] ovl_parse_param+0x809/0x1970 fs/overlayfs/params.c:624 vfs_parse_fs_param+0x428/0x890 fs/fs_context.c:146 vfs_parse_fs_string fs/fs_context.c:188 [inline] vfs_parse_monolithic_sep+0x44f/0x6a0 fs/fs_context.c:230 ovl_parse_monolithic+0x3d/0x50 fs/overlayfs/params.c:188 parse_monolithic_mount_data+0x6b/0x90 fs/fs_context.c:723 do_new_mount+0x58b/0x1420 fs/namespace.c:3804 path_mount+0x6db/0x1e90 fs/namespace.c:4123 do_mount fs/namespace.c:4136 [inline] __do_sys_mount fs/namespace.c:4347 [inline] __se_sys_mount+0x6eb/0x7d0 fs/namespace.c:4324 __x64_sys_mount+0xe4/0x150 fs/namespace.c:4324 x64_sys_call+0x3604/0x3e20 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Bytes 3468-3471 of 4096 are uninitialized Memory access of size 4096 starts at ffff88802c0a2000 Data copied to user address 000020000000fc40 CPU: 0 UID: 0 PID: 12899 Comm: syz.5.1738 Tainted: G W syzkaller #0 PREEMPT(none) Tainted: [W]=WARN Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 =====================================================