loop3: rw=524288, sector=1056, nr_sectors = 16 limit=16 syz.3.383: attempt to access beyond end of device loop3: rw=524288, sector=8, nr_sectors = 16 limit=16 ================================================================== BUG: KASAN: use-after-free in memcpy_to_page include/linux/highmem.h:403 [inline] BUG: KASAN: use-after-free in z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 Read of size 4096 at addr ffff0000dcbb2000 by task syz.3.383/5889 CPU: 1 PID: 5889 Comm: syz.3.383 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/26/2026 Call trace: dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 print_address_description+0x88/0x218 mm/kasan/report.c:316 print_report+0x50/0x68 mm/kasan/report.c:420 kasan_report+0xa8/0xfc mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x258/0x290 mm/kasan/generic.c:189 memcpy+0x48/0x90 mm/kasan/shadow.c:65 memcpy_to_page include/linux/highmem.h:403 [inline] z_erofs_transform_plain+0x3a4/0x490 fs/erofs/decompressor.c:346 z_erofs_decompress+0x9c/0xd4 fs/erofs/decompressor.c:434 z_erofs_decompress_pcluster fs/erofs/zdata.c:1159 [inline] z_erofs_decompress_queue+0x100c/0x1b40 fs/erofs/zdata.c:1240 z_erofs_runqueue+0x14d4/0x1694 fs/erofs/zdata.c:1597 z_erofs_read_folio+0x2d8/0x5c8 fs/erofs/zdata.c:1687 filemap_read_folio+0x134/0x384 mm/filemap.c:2490 filemap_update_page mm/filemap.c:2575 [inline] filemap_get_pages mm/filemap.c:2689 [inline] filemap_read+0x12cc/0x2104 mm/filemap.c:2759 generic_file_read_iter+0xf8/0x5c4 mm/filemap.c:2941 call_read_iter include/linux/fs.h:2259 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x3d4/0x7f0 fs/read_write.c:470 ksys_read+0x12c/0x224 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:621 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Allocated by task 5656: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x70/0x88 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x74/0x430 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x22c/0x308 mm/slub.c:3383 kmem_cache_zalloc include/linux/slab.h:689 [inline] __kernfs_new_node+0xec/0x5f4 fs/kernfs/dir.c:614 kernfs_new_node+0x11c/0x22c fs/kernfs/dir.c:690 __kernfs_create_file+0x60/0x2d4 fs/kernfs/file.c:1068 sysfs_add_file_mode_ns+0x1d8/0x294 fs/sysfs/file.c:294 create_files fs/sysfs/group.c:64 [inline] internal_create_group+0x3e0/0xad0 fs/sysfs/group.c:148 internal_create_groups fs/sysfs/group.c:188 [inline] sysfs_create_groups+0x60/0x134 fs/sysfs/group.c:214 create_dir lib/kobject.c:68 [inline] kobject_add_internal+0x5d4/0xb08 lib/kobject.c:231 kobject_add_varg lib/kobject.c:366 [inline] kobject_init_and_add+0x124/0x190 lib/kobject.c:449 netdev_queue_add_kobject net/core/net-sysfs.c:1664 [inline] netdev_queue_update_kobjects+0x1d0/0x43c net/core/net-sysfs.c:1716 register_queue_kobjects net/core/net-sysfs.c:1777 [inline] netdev_register_kobject+0x234/0x2e0 net/core/net-sysfs.c:2017 register_netdevice+0xf1c/0x160c net/core/dev.c:10230 __ip_tunnel_create+0x29c/0x3a8 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x238/0x628 net/ipv4/ip_tunnel.c:1104 vti_init_net+0x3c/0x120 net/ipv4/ip_vti.c:504 ops_init+0x2b0/0x53c net/core/net_namespace.c:138 setup_net+0x474/0xb34 net/core/net_namespace.c:336 copy_net_ns+0x2b8/0x578 net/core/net_namespace.c:508 create_new_namespaces+0x318/0x5ec kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x108/0x158 kernel/nsproxy.c:226 ksys_unshare+0x3e0/0x6dc kernel/fork.c:3282 __do_sys_unshare kernel/fork.c:3353 [inline] __se_sys_unshare kernel/fork.c:3351 [inline] __arm64_sys_unshare+0x3c/0x50 kernel/fork.c:3351 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 Freed by task 4467: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4c/0x80 mm/kasan/common.c:53 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:516 ____kasan_slab_free+0x148/0x1b0 mm/kasan/common.c:237 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:245 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1729 [inline] slab_free_freelist_hook+0x16c/0x1e8 mm/slub.c:1755 slab_free mm/slub.c:3687 [inline] kmem_cache_free+0x118/0x314 mm/slub.c:3709 kernfs_put+0x2f4/0x498 fs/kernfs/dir.c:568 kernfs_remove_by_name_ns+0xe8/0x180 fs/kernfs/dir.c:1668 kernfs_remove_by_name include/linux/kernfs.h:622 [inline] remove_files fs/sysfs/group.c:28 [inline] sysfs_remove_group+0xf8/0x280 fs/sysfs/group.c:288 sysfs_remove_groups+0x5c/0xb4 fs/sysfs/group.c:312 __kobject_del+0x90/0x2d0 lib/kobject.c:587 kobject_cleanup lib/kobject.c:672 [inline] kobject_release lib/kobject.c:712 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2c0/0x420 lib/kobject.c:729 netdev_queue_update_kobjects+0x3b4/0x43c net/core/net-sysfs.c:1731 remove_queue_kobjects net/core/net-sysfs.c:1828 [inline] netdev_unregister_kobject+0xf0/0x204 net/core/net-sysfs.c:1981 unregister_netdevice_many+0x11dc/0x177c net/core/dev.c:11043 ip_tunnel_delete_nets+0x2d0/0x32c net/ipv4/ip_tunnel.c:1157 vti_exit_batch_net+0x30/0x54 net/ipv4/ip_vti.c:515 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x650/0xa84 net/core/net_namespace.c:640 process_one_work+0x7f8/0x13a4 kernel/workqueue.c:2292 worker_thread+0x8c4/0xfec kernel/workqueue.c:2439 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 The buggy address belongs to the object at ffff0000dcbb2000 which belongs to the cache kernfs_node_cache of size 168 The buggy address is located 0 bytes inside of 168-byte region [ffff0000dcbb2000, ffff0000dcbb20a8) The buggy address belongs to the physical page: page:000000003e362758 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11cbb2 flags: 0x5ffc00000000200(slab|node=0|zone=2|lastcpupid=0x7ff) raw: 05ffc00000000200 0000000000000000 dead000000000122 ffff0000c03dca80 raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000dcbb1f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff0000dcbb1f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff0000dcbb2000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000dcbb2080: fb fb fb fb fb fc fc fc fc fc fc fc fc fa fb fb ffff0000dcbb2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== syz.3.383: attempt to access beyond end of device loop3: rw=0, sector=1056, nr_sectors = 8 limit=16