================================================================== BUG: KASA[ 730.192938][ T7920] BUG: KASAN: slab-use-after-free in kbd_keycode drivers/tty/vt/keyboard.c:1435 [inline] BUG: KASA[ 730.192938][ T7920] BUG: KASAN: slab-use-after-free in kbd_event+0x3330/0x40d0 drivers/tty/vt/keyboard.c:1515 Read of size 4 at addr ffff88806944e35c by task syz.2.13424/7920 CPU: 1 UID: 0 PID: 7920 Comm: syz.2.13424 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 kbd_keycode drivers/tty/vt/keyboard.c:1435 [inline] kbd_event+0x3330/0x40d0 drivers/tty/vt/keyboard.c:1515 input_handle_events_default+0xd4/0x1a0 drivers/input/input.c:2541 input_pass_values+0x288/0x890 drivers/input/input.c:128 input_event_dispose+0x330/0x6b0 drivers/input/input.c:342 input_inject_event+0x1d8/0x330 drivers/input/input.c:424 evdev_write+0x328/0x4c0 drivers/input/evdev.c:528 vfs_write+0x2a3/0xba0 fs/read_write.c:686 ksys_write+0x156/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5547bac819 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:00007f5545dfe028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f5547e25fa0 RCX: 00007f5547bac819 RDX: 0000000000002250 RSI: 0000200000000040 RDI: 0000000000000003 RBP: 00007f5547c42c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5547e26038 R14: 00007f5547e25fa0 R15: 00007ffe04f8cf48 Allocated by task 7915: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x3a6/0x690 mm/slub.c:5380 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] alloc_tty_struct+0xa6/0x7b0 drivers/tty/tty_io.c:3102 tty_init_dev+0x59/0x4d0 drivers/tty/tty_io.c:1400 tty_open_by_driver drivers/tty/tty_io.c:2073 [inline] tty_open+0x86e/0xd80 drivers/tty/tty_io.c:2120 chrdev_open+0x4d0/0x5f0 fs/char_dev.c:411 do_dentry_open+0x83d/0x13e0 fs/open.c:949 vfs_open+0x3b/0x350 fs/open.c:1081 do_open fs/namei.c:4677 [inline] path_openat+0x2e43/0x38a0 fs/namei.c:4836 do_file_open+0x23e/0x4a0 fs/namei.c:4865 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15095: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2685 [inline] slab_free mm/slub.c:6165 [inline] kfree+0x1c1/0x6c0 mm/slub.c:6483 process_one_work kernel/workqueue.c:3276 [inline] process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2199 __queue_work+0xcc6/0xff0 kernel/workqueue.c:2354 queue_work_on+0x106/0x1d0 kernel/workqueue.c:2405 tty_release_struct+0xb8/0xd0 drivers/tty/tty_io.c:1692 tty_release+0xcb6/0x1710 drivers/tty/tty_io.c:1852 __fput+0x461/0xa90 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88806944e000 which belongs to the cache kmalloc-cg-2k of size 2048 The buggy address is located 860 bytes inside of freed 2048-byte region [ffff88806944e000, ffff88806944e800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x69448 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888069448811 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff88813fe363c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000100000080008 00000000f5000000 ffff888069448811 head: 0080000000000040 ffff88813fe363c0 dead000000000100 dead000000000122 head: 0000000000000000 0000100000080008 00000000f5000000 ffff888069448811 head: 0080000000000003 ffffea0001a51201 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 5878, tgid 5878 (syz-executor), ts 463972954830, free_ts 463959021215 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x77/0x660 mm/slub.c:3481 new_slab mm/slub.c:3539 [inline] refill_objects+0x334/0x3c0 mm/slub.c:7175 refill_sheaf mm/slub.c:2812 [inline] __pcs_replace_empty_main+0x35c/0x710 mm/slub.c:4615 alloc_from_pcs mm/slub.c:4717 [inline] slab_alloc_node mm/slub.c:4851 [inline] __do_kmalloc_node mm/slub.c:5259 [inline] __kvmalloc_node_noprof+0x6f4/0x8e0 mm/slub.c:6752 alloc_fdtable+0x101/0x2c0 fs/file.c:219 dup_fd+0x879/0xb70 fs/file.c:420 copy_files+0xc8/0x120 kernel/fork.c:1636 copy_process+0x1767/0x3cd0 kernel/fork.c:2211 kernel_clone+0x249/0x840 kernel/fork.c:2653 __do_sys_clone kernel/fork.c:2794 [inline] __se_sys_clone kernel/fork.c:2778 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2778 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 1186 tgid 1186 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978 __folio_put+0x25d/0x310 mm/swap.c:112 put_netmem include/net/netmem.h:420 [inline] skb_page_unref include/linux/skbuff_ref.h:43 [inline] __skb_frag_unref include/linux/skbuff_ref.h:56 [inline] skb_release_data+0x4cb/0x940 net/core/skbuff.c:1122 skb_release_all net/core/skbuff.c:1203 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1217 skb_defer_free_flush+0x191/0x260 net/core/dev.c:6837 net_rx_action+0x4a6/0xe00 net/core/dev.c:7910 handle_softirqs+0x1de/0x6f0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] irq_forced_thread_fn+0xe9/0x120 kernel/irq/manage.c:1168 irq_thread+0x4c9/0x740 kernel/irq/manage.c:1271 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: ffff88806944e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806944e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806944e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806944e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806944e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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