================================================================== BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline] BUG: KASAN: use-after-free in atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline] BUG: KASAN: use-after-free in atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline] BUG: KASAN: use-after-free in __mutex_trylock_fast kernel/locking/mutex.c:173 [inline] BUG: KASAN: use-after-free in mutex_lock+0x7f/0xe0 kernel/locking/mutex.c:298 Write of size 8 at addr ffff888119ae9440 by task syz.1.6145/18807 CPU: 0 PID: 18807 Comm: syz.1.6145 Tainted: G W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 mm/kasan/generic.c:189 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37 instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic64_try_cmpxchg_acquire include/asm-generic/atomic-instrumented.h:1515 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:443 [inline] __mutex_trylock_fast kernel/locking/mutex.c:173 [inline] mutex_lock+0x7f/0xe0 kernel/locking/mutex.c:298 steam_input_open+0x91/0x160 drivers/hid/hid-steam.c:297 input_open_device+0x14c/0x2a0 drivers/input/input.c:635 evdev_open_device drivers/input/evdev.c:400 [inline] evdev_open+0x4d2/0x5e0 drivers/input/evdev.c:487 chrdev_open+0x597/0x670 fs/char_dev.c:414 do_dentry_open+0x793/0x1090 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x27ad/0x3160 fs/namei.c:3509 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1244 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6149e3c510 Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44 RSP: 002b:00007f61488a5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6149e3c510 RDX: 0000000000000000 RSI: 00007f61488a5c10 RDI: 00000000ffffff9c RBP: 00007f61488a5c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f614a085038 R14: 00007f614a084fa0 R15: 00007ffc81036f58 Allocated by task 18480: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:430 [inline] ____kasan_kmalloc mm/kasan/common.c:509 [inline] __kasan_kmalloc+0xda/0x110 mm/kasan/common.c:518 kasan_kmalloc include/linux/kasan.h:254 [inline] __kmalloc+0x1a7/0x330 mm/slub.c:4038 kmalloc_array include/linux/slab.h:592 [inline] kcalloc include/linux/slab.h:603 [inline] kvm_create_vm_debugfs virt/kvm/kvm_main.c:759 [inline] kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:4103 [inline] kvm_dev_ioctl+0xf28/0x1610 virt/kvm/kvm_main.c:4130 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl+0x121/0x1a0 fs/ioctl.c:739 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:739 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 18479: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370 kasan_slab_free include/linux/kasan.h:220 [inline] slab_free_hook mm/slub.c:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kfree+0xc0/0x270 mm/slub.c:4196 kvm_destroy_vm_debugfs virt/kvm/kvm_main.c:729 [inline] kvm_destroy_vm virt/kvm/kvm_main.c:925 [inline] kvm_put_kvm+0x1e1/0x10d0 virt/kvm/kvm_main.c:968 kvm_vm_release+0x46/0x50 virt/kvm/kvm_main.c:991 __fput+0x2fb/0x770 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888119ae9400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 64 bytes inside of 512-byte region [ffff888119ae9400, ffff888119ae9600) The buggy address belongs to the page: page:ffffea000466ba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888119aebc00 pfn:0x119ae8 head:ffffea000466ba00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00047c2a08 ffffea0004938408 ffff888100043080 raw: ffff888119aebc00 000000000010000f 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 653, ts 308784164595, free_ts 308206399605 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] __kmalloc+0x201/0x330 mm/slub.c:4034 kmalloc include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:664 [inline] fib6_info_alloc+0x34/0xe0 net/ipv6/ip6_fib.c:154 ip6_route_info_create+0x4d2/0x1490 net/ipv6/route.c:3673 ip6_route_add+0x27/0x130 net/ipv6/route.c:3769 addrconf_add_mroute net/ipv6/addrconf.c:2527 [inline] addrconf_add_dev+0x329/0x430 net/ipv6/addrconf.c:2545 addrconf_dev_config+0x1bd/0x510 net/ipv6/addrconf.c:3427 addrconf_notify+0x9d8/0xe90 net/ipv6/addrconf.c:3673 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 call_netdevice_notifiers_info net/core/dev.c:2054 [inline] netdev_state_change+0x16a/0x210 net/core/dev.c:1484 linkwatch_do_dev+0x102/0x140 net/core/link_watch.c:167 page last free stack trace: reset_page_owner include/linux/page_owner.h:28 [inline] free_pages_prepare mm/page_alloc.c:1349 [inline] free_pcp_prepare mm/page_alloc.c:1421 [inline] free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page mm/page_alloc.c:3391 [inline] free_the_page mm/page_alloc.c:5429 [inline] __free_pages+0x14b/0x380 mm/page_alloc.c:5440 __vunmap+0x84d/0x9d0 mm/vmalloc.c:2307 __vfree mm/vmalloc.c:2356 [inline] vfree+0x61/0x90 mm/vmalloc.c:2387 kcov_put kernel/kcov.c:408 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:510 __fput+0x2fb/0x770 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x127/0x190 kernel/task_work.c:189 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa4f/0x2480 kernel/exit.c:872 do_group_exit+0x141/0x310 kernel/exit.c:986 get_signal+0xf7d/0x12e0 kernel/signal.c:2793 arch_do_signal_or_restart+0xbf/0x10f0 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 Memory state around the buggy address: ffff888119ae9300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888119ae9380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888119ae9400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888119ae9480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888119ae9500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ================================================================================ UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.c:130:9 index 2501 is out of range for type 'unsigned long[8]' CPU: 0 PID: 18807 Comm: syz.1.6145 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 dump_stack+0x15/0x1c lib/dump_stack.c:135 ubsan_epilogue+0xe/0x40 lib/ubsan.c:148 __ubsan_handle_out_of_bounds+0xdf/0xf0 lib/ubsan.c:347 decode_tail kernel/locking/qspinlock.c:130 [inline] __pv_queued_spin_lock_slowpath+0xaec/0xb70 kernel/locking/qspinlock.c:468 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline] queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock include/linux/spinlock.h:183 [inline] __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_lock+0xd8/0xe0 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] __mutex_lock_common kernel/locking/mutex.c:985 [inline] __mutex_lock+0x342/0xc50 kernel/locking/mutex.c:1117 __mutex_lock_slowpath+0xe/0x10 kernel/locking/mutex.c:1379 mutex_lock+0xcf/0xe0 kernel/locking/mutex.c:299 steam_input_open+0x91/0x160 drivers/hid/hid-steam.c:297 input_open_device+0x14c/0x2a0 drivers/input/input.c:635 evdev_open_device drivers/input/evdev.c:400 [inline] evdev_open+0x4d2/0x5e0 drivers/input/evdev.c:487 chrdev_open+0x597/0x670 fs/char_dev.c:414 do_dentry_open+0x793/0x1090 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x27ad/0x3160 fs/namei.c:3509 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1244 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6149e3c510 Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44 RSP: 002b:00007f61488a5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6149e3c510 RDX: 0000000000000000 RSI: 00007f61488a5c10 RDI: 00000000ffffff9c RBP: 00007f61488a5c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f614a085038 R14: 00007f614a084fa0 R15: 00007ffc81036f58 ================================================================================ general protection fault, probably for non-canonical address 0xdffffc0000148147: 0000 [#1] PREEMPT SMP KASAN KASAN: probably user-memory-access in range [0x0000000000a40a38-0x0000000000a40a3f] CPU: 0 PID: 18807 Comm: syz.1.6145 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 RIP: 0010:__pv_queued_spin_lock_slowpath+0x2c8/0xb70 kernel/locking/qspinlock.c:471 Code: 00 74 18 49 89 d7 48 89 d7 e8 34 71 52 00 48 be 00 00 00 00 00 fc ff df 4c 89 fa 4c 8b 7c 24 10 4c 03 3a 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 08 4c 89 ff e8 aa 71 52 00 48 8b 44 24 20 49 89 07 RSP: 0018:ffffc90000e37320 EFLAGS: 00010206 RAX: 0000000000148147 RBX: ffff888119ae9448 RCX: 0000000000057280 RDX: ffffffff859c94e8 RSI: dffffc0000000000 RDI: 0000000000080000 RBP: ffffc90000e37410 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0d8ee48 R11: 1ffffffff0d8ee48 R12: 1ffff1103ee0ae49 R13: 1ffff1102335d289 R14: ffff8881f7057254 R15: 0000000000a40a39 FS: 00007f61488a66c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6148885d58 CR3: 000000013182a000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:554 [inline] queued_spin_lock_slowpath+0x47/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock include/linux/spinlock.h:183 [inline] __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_lock+0xd8/0xe0 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] __mutex_lock_common kernel/locking/mutex.c:985 [inline] __mutex_lock+0x342/0xc50 kernel/locking/mutex.c:1117 __mutex_lock_slowpath+0xe/0x10 kernel/locking/mutex.c:1379 mutex_lock+0xcf/0xe0 kernel/locking/mutex.c:299 steam_input_open+0x91/0x160 drivers/hid/hid-steam.c:297 input_open_device+0x14c/0x2a0 drivers/input/input.c:635 evdev_open_device drivers/input/evdev.c:400 [inline] evdev_open+0x4d2/0x5e0 drivers/input/evdev.c:487 chrdev_open+0x597/0x670 fs/char_dev.c:414 do_dentry_open+0x793/0x1090 fs/open.c:819 vfs_open+0x73/0x80 fs/open.c:942 do_open fs/namei.c:3391 [inline] path_openat+0x27ad/0x3160 fs/namei.c:3509 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1244 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f6149e3c510 Code: 48 89 44 24 20 75 93 44 89 54 24 0c e8 49 94 02 00 44 8b 54 24 0c 89 da 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 38 44 89 c7 89 44 24 0c e8 9c 94 02 00 8b 44 RSP: 002b:00007f61488a5b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6149e3c510 RDX: 0000000000000000 RSI: 00007f61488a5c10 RDI: 00000000ffffff9c RBP: 00007f61488a5c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007f614a085038 R14: 00007f614a084fa0 R15: 00007ffc81036f58 Modules linked in: ---[ end trace 937c3b2a11a09f2a ]--- RIP: 0010:__pv_queued_spin_lock_slowpath+0x2c8/0xb70 kernel/locking/qspinlock.c:471 Code: 00 74 18 49 89 d7 48 89 d7 e8 34 71 52 00 48 be 00 00 00 00 00 fc ff df 4c 89 fa 4c 8b 7c 24 10 4c 03 3a 4c 89 f8 48 c1 e8 03 <80> 3c 30 00 74 08 4c 89 ff e8 aa 71 52 00 48 8b 44 24 20 49 89 07 RSP: 0018:ffffc90000e37320 EFLAGS: 00010206 RAX: 0000000000148147 RBX: ffff888119ae9448 RCX: 0000000000057280 RDX: ffffffff859c94e8 RSI: dffffc0000000000 RDI: 0000000000080000 RBP: ffffc90000e37410 R08: 0000000000000004 R09: 0000000000000003 R10: fffffbfff0d8ee48 R11: 1ffffffff0d8ee48 R12: 1ffff1103ee0ae49 R13: 1ffff1102335d289 R14: ffff8881f7057254 R15: 0000000000a40a39 FS: 00007f61488a66c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6148885d58 CR3: 000000013182a000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 00 74 18 49 add %dh,0x49(%rax,%rbx,1) 4: 89 d7 mov %edx,%edi 6: 48 89 d7 mov %rdx,%rdi 9: e8 34 71 52 00 call 0x527142 e: 48 be 00 00 00 00 00 movabs $0xdffffc0000000000,%rsi 15: fc ff df 18: 4c 89 fa mov %r15,%rdx 1b: 4c 8b 7c 24 10 mov 0x10(%rsp),%r15 20: 4c 03 3a add (%rdx),%r15 23: 4c 89 f8 mov %r15,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 30 00 cmpb $0x0,(%rax,%rsi,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 ff mov %r15,%rdi 33: e8 aa 71 52 00 call 0x5271e2 38: 48 8b 44 24 20 mov 0x20(%rsp),%rax 3d: 49 89 07 mov %rax,(%r15)