================================================================== BUG: KASAN: slab-use-after-free in release_tty+0x5a8/0x5f0 drivers/tty/tty_io.c:1584 Write of size 8 at addr ffff88803487f128 by task syz.4.4594/23193 CPU: 0 UID: 0 PID: 23193 Comm: syz.4.4594 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 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 release_tty+0x5a8/0x5f0 drivers/tty/tty_io.c:1584 tty_release_struct+0xb7/0xe0 drivers/tty/tty_io.c:1692 tty_release+0xd7a/0x1300 drivers/tty/tty_io.c:1852 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 get_signal+0x1bd/0x21e0 kernel/signal.c:2818 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x6f0 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+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fad4599e0d9 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:00007fad468d8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: fffffffffffffe00 RBX: 00007fad45c26090 RCX: 00007fad4599e0d9 RDX: 0000000000000001 RSI: 0000200000000a00 RDI: 0000000000000006 RBP: 00007fad45a35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fad45c26128 R14: 00007fad45c26090 R15: 00007ffe36320cc8 Allocated by task 8740: 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+0xaa/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5489 _kmalloc_noprof include/linux/slab.h:988 [inline] _kzalloc_noprof include/linux/slab.h:1309 [inline] gs_port_alloc drivers/usb/gadget/function/u_serial.c:1218 [inline] gserial_alloc_line_no_console+0xac/0x710 drivers/usb/gadget/function/u_serial.c:1298 obex_alloc_inst+0x86/0x100 drivers/usb/gadget/function/f_obex.c:434 try_get_usb_function_instance+0x136/0x1f0 drivers/usb/gadget/functions.c:28 usb_get_function_instance+0x16/0x70 drivers/usb/gadget/functions.c:44 function_make+0x18c/0x3f0 drivers/usb/gadget/configfs.c:626 configfs_mkdir+0x51e/0xb70 fs/configfs/dir.c:1360 vfs_mkdir+0x361/0x850 fs/namei.c:5276 filename_mkdirat+0x48b/0x5e0 fs/namei.c:5309 __do_sys_mkdirat fs/namei.c:5330 [inline] __se_sys_mkdirat fs/namei.c:5327 [inline] __x64_sys_mkdirat+0x89/0xc0 fs/namei.c:5327 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 23197: 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+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2677 [inline] slab_free mm/slub.c:6377 [inline] kfree+0x22b/0x6c0 mm/slub.c:6692 gserial_free_port+0x146/0x2f0 drivers/usb/gadget/function/u_serial.c:1262 gserial_free_line+0xf8/0x1e0 drivers/usb/gadget/function/u_serial.c:1279 obex_free_inst+0x3b/0x50 drivers/usb/gadget/function/f_obex.c:420 usb_put_function_instance+0x89/0xc0 drivers/usb/gadget/functions.c:77 config_item_cleanup+0x146/0x240 fs/configfs/item.c:128 config_item_release fs/configfs/item.c:137 [inline] kref_put include/linux/kref.h:65 [inline] config_item_put fs/configfs/item.c:149 [inline] config_item_put+0x93/0xb0 fs/configfs/item.c:146 configfs_rmdir+0x5e3/0x950 fs/configfs/dir.c:1571 vfs_rmdir fs/namei.c:5381 [inline] vfs_rmdir+0x328/0x8a0 fs/namei.c:5354 filename_rmdir+0x31a/0x5c0 fs/namei.c:5438 __do_sys_rmdir fs/namei.c:5461 [inline] __se_sys_rmdir fs/namei.c:5458 [inline] __x64_sys_rmdir+0x46/0x70 fs/namei.c:5458 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88803487f000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 296 bytes inside of freed 2048-byte region [ffff88803487f000, ffff88803487f800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803487c000 pfn:0x34878 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88813fe28000 ffffea0001fa6a10 ffffea000158d010 raw: ffff88803487c000 0000000800080006 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88813fe28000 ffffea0001fa6a10 ffffea000158d010 head: ffff88803487c000 0000000800080006 00000000f5000000 0000000000000000 head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5608, tgid 5608 (syz-executor), ts 68804263185, free_ts 68789261014 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3266 [inline] allocate_slab mm/slub.c:3380 [inline] new_slab+0xa2/0x640 mm/slub.c:3426 refill_objects+0xe3/0x410 mm/slub.c:7310 refill_sheaf mm/slub.c:2804 [inline] __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675 alloc_from_pcs mm/slub.c:4773 [inline] slab_alloc_node mm/slub.c:4905 [inline] __do_kmalloc_node mm/slub.c:5333 [inline] __kmalloc_node_track_caller_noprof+0x679/0x830 mm/slub.c:5471 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:637 pskb_expand_head+0x249/0x10e0 net/core/skbuff.c:2312 netlink_trim+0x22d/0x2f0 net/netlink/af_netlink.c:1300 netlink_broadcast_filtered+0x6d/0xf20 net/netlink/af_netlink.c:1518 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0xb1/0x290 net/netlink/af_netlink.c:2599 rtnl_notify net/core/rtnetlink.c:963 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:4553 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4569 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4556 [inline] rtnetlink_event+0x1b3/0x1f0 net/core/rtnetlink.c:7136 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2250 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline] call_netdevice_notifiers net/core/dev.c:2302 [inline] netif_set_mac_address+0x370/0x4a0 net/core/dev.c:10002 page last free pid 5730 tgid 5730 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_node_noprof+0x27d/0x6b0 mm/slub.c:4989 __alloc_skb+0x140/0x710 net/core/skbuff.c:704 alloc_skb include/linux/skbuff.h:1384 [inline] mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1789 add_grhead+0x299/0x340 net/ipv6/mcast.c:1900 add_grec+0x1389/0x1930 net/ipv6/mcast.c:2039 mld_send_initial_cr+0x156/0x320 net/ipv6/mcast.c:2284 mld_dad_work+0x32/0x1f0 net/ipv6/mcast.c:2310 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88803487f000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803487f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88803487f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88803487f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88803487f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================