================================================================== BUG: KASAN: slab-use-after-free in strlen+0x85/0xa0 lib/string.c:402 Read of size 1 at addr ffff88810469d798 by task syz.4.1104/9677 CPU: 1 UID: 0 PID: 9677 Comm: syz.4.1104 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 strlen+0x85/0xa0 lib/string.c:402 __fortify_strlen include/linux/fortify-string.h:218 [inline] str_to_user+0x26/0xa0 drivers/input/evdev.c:774 evdev_do_ioctl+0x1322/0x1b30 drivers/input/evdev.c:1177 evdev_ioctl_handler drivers/input/evdev.c:1275 [inline] evdev_ioctl+0x16f/0x1a0 drivers/input/evdev.c:1284 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x119/0x710 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc863c7e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc8626d7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc863f05fa0 RCX: 00007fc863c7e159 RDX: 0000200000000140 RSI: 0000000080404507 RDI: 0000000000000004 RBP: 00007fc863d1506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc863f06038 R14: 00007fc863f05fa0 R15: 00007fff125c7738 Allocated by task 5599: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_node_track_caller_noprof+0x323/0x820 mm/slub.c:5545 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:637 __alloc_skb+0x185/0x710 net/core/skbuff.c:715 alloc_skb include/linux/skbuff.h:1384 [inline] nlmsg_new include/net/netlink.h:1055 [inline] rtmsg_ifinfo_build_skb+0x81/0x260 net/core/rtnetlink.c:4580 unregister_netdevice_many_notify+0x18f1/0x1fb0 net/core/dev.c:12521 unregister_netdevice_many net/core/dev.c:12589 [inline] unregister_netdevice_queue net/core/dev.c:12390 [inline] unregister_netdevice_queue+0x30b/0x3c0 net/core/dev.c:12376 unregister_netdevice include/linux/netdevice.h:3487 [inline] unregister_netdev+0x1f/0x60 net/core/dev.c:12697 kaweth_disconnect+0x91/0x320 drivers/net/usb/kaweth.c:1113 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:618 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:610 __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:664 device_del+0x376/0x9b0 drivers/base/core.c:3965 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2350 hub_port_connect drivers/usb/core/hub.c:5420 [inline] hub_port_connect_change drivers/usb/core/hub.c:5720 [inline] port_event drivers/usb/core/hub.c:5884 [inline] hub_event+0x1d46/0x4510 drivers/usb/core/hub.c:5966 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 2900: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x20c/0x650 mm/slub.c:6792 skb_kfree_head net/core/skbuff.c:1083 [inline] skb_free_head+0xb9/0x160 net/core/skbuff.c:1095 skb_release_data+0x6c5/0x8e0 net/core/skbuff.c:1122 skb_release_all net/core/skbuff.c:1197 [inline] __kfree_skb net/core/skbuff.c:1211 [inline] consume_skb net/core/skbuff.c:1448 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1442 netlink_recvmsg+0x51b/0x9c0 net/netlink/af_netlink.c:1978 sock_recvmsg_nosec net/socket.c:1151 [inline] sock_recvmsg+0x1d5/0x220 net/socket.c:1173 ____sys_recvmsg+0x21e/0x670 net/socket.c:2933 ___sys_recvmsg+0x16a/0x1a0 net/socket.c:2975 __sys_recvmsg net/socket.c:3008 [inline] __do_sys_recvmsg net/socket.c:3014 [inline] __se_sys_recvmsg net/socket.c:3011 [inline] __x64_sys_recvmsg+0x19a/0x260 net/socket.c:3011 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x119/0x710 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88810469d000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1944 bytes inside of freed 2048-byte region [ffff88810469d000, ffff88810469d800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x104698 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042000 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888100042000 dead000000000100 dead000000000122 head: 0000000000000000 0000000000080008 00000000f5000000 0000000000000000 head: 0200000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2985965497 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0xf4b/0x3440 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2d7/0x2f70 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab mm/slub.c:3462 [inline] new_slab+0xa9/0x6e0 mm/slub.c:3513 refill_objects+0xe3/0x410 mm/slub.c:7410 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __kmalloc_cache_noprof+0x4a1/0x680 mm/slub.c:5559 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] acpi_ds_create_walk_state+0x95/0x300 drivers/acpi/acpica/dswstate.c:518 acpi_ds_auto_serialize_method+0x1a1/0x3f0 drivers/acpi/acpica/dsmethod.c:81 acpi_ds_init_one_object drivers/acpi/acpica/dsinit.c:110 [inline] acpi_ds_init_one_object+0x362/0x450 drivers/acpi/acpica/dsinit.c:46 acpi_ns_walk_namespace+0x4cc/0x760 drivers/acpi/acpica/nswalk.c:236 acpi_ds_initialize_objects+0x172/0x730 drivers/acpi/acpica/dsinit.c:189 acpi_ns_load_table+0x1b9/0x490 drivers/acpi/acpica/nsload.c:106 acpi_tb_load_namespace+0x2b0/0x8f0 drivers/acpi/acpica/tbxfload.c:158 acpi_load_tables+0x89/0x160 drivers/acpi/acpica/tbxfload.c:59 acpi_bus_init drivers/acpi/bus.c:1373 [inline] acpi_init+0x146/0x840 drivers/acpi/bus.c:1486 page_owner free stack trace missing Memory state around the buggy address: ffff88810469d680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88810469d700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88810469d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810469d800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88810469d880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================