================================================================== 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 ffff888126a2fc40 by task syz.3.4545/16253 CPU: 1 PID: 16253 Comm: syz.3.4545 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: 0033:0x7fad26910510 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:00007fad25379b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000020200 RCX: 00007fad26910510 RDX: 0000000000020200 RSI: 00007fad25379c10 RDI: 00000000ffffff9c RBP: 00007fad25379c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007fad26b59038 R14: 00007fad26b58fa0 R15: 00007ffd3470da88 Allocated by task 390: 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 include/linux/slab.h:557 [inline] kzalloc include/linux/slab.h:664 [inline] neigh_alloc net/core/neighbour.c:439 [inline] ___neigh_create+0x6f0/0x1a20 net/core/neighbour.c:592 __neigh_create+0x31/0x40 net/core/neighbour.c:680 ip6_finish_output2+0x8d1/0x1500 net/ipv6/ip6_output.c:127 __ip6_finish_output+0x5ff/0x790 net/ipv6/ip6_output.c:201 ip6_finish_output+0x33/0x1f0 net/ipv6/ip6_output.c:211 NF_HOOK_COND include/linux/netfilter.h:288 [inline] ip6_output+0x1d1/0x3b0 net/ipv6/ip6_output.c:234 dst_output include/net/dst.h:451 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ndisc_send_skb+0x6f5/0xb40 net/ipv6/ndisc.c:513 ndisc_send_ns+0x842/0xaf0 net/ipv6/ndisc.c:655 addrconf_dad_work+0x9de/0x1410 net/ipv6/addrconf.c:4210 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Freed by task 77: 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 skb_free_head net/core/skbuff.c:606 [inline] skb_release_data+0x532/0x670 net/core/skbuff.c:626 skb_release_all net/core/skbuff.c:680 [inline] __kfree_skb net/core/skbuff.c:694 [inline] consume_skb+0xab/0x1f0 net/core/skbuff.c:851 skb_free_datagram+0x28/0xe0 net/core/datagram.c:325 unix_dgram_recvmsg+0x9c0/0xd40 net/unix/af_unix.c:2233 sock_recvmsg_nosec net/socket.c:905 [inline] sock_recvmsg net/socket.c:923 [inline] sock_read_iter+0x2a2/0x340 net/socket.c:996 call_read_iter include/linux/fs.h:2060 [inline] new_sync_read fs/read_write.c:415 [inline] vfs_read+0x874/0xa10 fs/read_write.c:496 ksys_read+0x140/0x240 fs/read_write.c:634 __do_sys_read fs/read_write.c:644 [inline] __se_sys_read fs/read_write.c:642 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:642 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 kvfree_call_rcu+0x10c/0x620 kernel/rcu/tree.c:3539 neigh_destroy+0x445/0x570 net/core/neighbour.c:865 neigh_release include/net/neighbour.h:427 [inline] neigh_cleanup_and_release+0x76/0x1a0 net/core/neighbour.c:104 neigh_periodic_work+0x833/0xa40 net/core/neighbour.c:952 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358 kvfree_call_rcu+0x10c/0x620 kernel/rcu/tree.c:3539 neigh_destroy+0x445/0x570 net/core/neighbour.c:865 neigh_release include/net/neighbour.h:427 [inline] neigh_cleanup_and_release+0x76/0x1a0 net/core/neighbour.c:104 neigh_flush_dev+0x642/0x820 net/core/neighbour.c:375 __neigh_ifdown+0x3f/0x380 net/core/neighbour.c:392 neigh_ifdown+0x1f/0x30 net/core/neighbour.c:409 rt6_disable_ip+0x616/0x6a0 net/ipv6/route.c:4802 addrconf_ifdown+0x144/0x1800 net/ipv6/addrconf.c:3788 addrconf_notify+0x3bd/0xe90 net/ipv6/addrconf.c:-1 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] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] dev_close_many+0x330/0x4d0 net/core/dev.c:1655 unregister_netdevice_many+0x44c/0x1980 net/core/dev.c:10744 default_device_exit_batch+0x330/0x390 net/core/dev.c:11287 ops_exit_list net/core/net_namespace.c:190 [inline] cleanup_net+0x5fb/0xb70 net/core/net_namespace.c:609 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301 worker_thread+0xa6a/0x13b0 kernel/workqueue.c:2447 kthread+0x346/0x3d0 kernel/kthread.c:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff888126a2fc00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 64 bytes inside of 512-byte region [ffff888126a2fc00, ffff888126a2fe00) The buggy address belongs to the page: page:ffffea00049a8b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x126a2c head:ffffea00049a8b00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea00049d7600 0000000300000002 ffff888100043080 raw: 0000000000000000 0000000000100010 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 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 278, ts 21659518271, free_ts 0 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_prefix_route net/ipv6/addrconf.c:2463 [inline] fixup_permanent_addr net/ipv6/addrconf.c:3519 [inline] addrconf_permanent_addr+0x5e8/0x8c0 net/ipv6/addrconf.c:3543 addrconf_notify+0x752/0xe90 net/ipv6/addrconf.c:3611 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] call_netdevice_notifiers_extack net/core/dev.c:2066 [inline] call_netdevice_notifiers net/core/dev.c:2080 [inline] __dev_notify_flags+0x28f/0x500 net/core/dev.c:-1 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8610 do_setlink+0xbb4/0x3ab0 net/core/rtnetlink.c:2732 page_owner free stack trace missing Memory state around the buggy address: ffff888126a2fb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888126a2fb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888126a2fc00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888126a2fc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888126a2fd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== general protection fault, probably for non-canonical address 0xef0601e6a6af060a: 0000 [#1] PREEMPT SMP KASAN KASAN: maybe wild-memory-access in range [0x78302f3535783050-0x78302f3535783057] CPU: 0 PID: 16253 Comm: syz.3.4545 Tainted: G B W syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2025 RIP: 0010:mutex_can_spin_on_owner kernel/locking/mutex.c:620 [inline] RIP: 0010:mutex_optimistic_spin kernel/locking/mutex.c:664 [inline] RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:976 [inline] RIP: 0010:__mutex_lock+0x18e/0xc50 kernel/locking/mutex.c:1117 Code: 42 80 3c 28 00 74 08 48 89 df e8 6d 5c 26 fd 4c 8b 3b 49 83 e7 f8 0f 84 93 00 00 00 4c 89 e9 4d 8d 6f 2c 4c 89 e8 48 c1 e8 03 <0f> b6 04 08 84 c0 0f 85 64 08 00 00 41 83 7d 00 00 0f 84 24 01 00 RSP: 0018:ffffc90000f8f4e0 EFLAGS: 00010207 RAX: 0f0605e6a6af060a RBX: ffff888126a2fc40 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888126a2fc40 RBP: ffffc90000f8f600 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed1024d45f88 R11: 1ffff11024d45f88 R12: ffff888127dbcf00 R13: 78302f3535783054 R14: 0000000000000003 R15: 78302f3535783028 FS: 00007fad2537a6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2a1385 CR3: 00000001249e0000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __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: 0033:0x7fad26910510 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:00007fad25379b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000020200 RCX: 00007fad26910510 RDX: 0000000000020200 RSI: 00007fad25379c10 RDI: 00000000ffffff9c RBP: 00007fad25379c10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007fad26b59038 R14: 00007fad26b58fa0 R15: 00007ffd3470da88 Modules linked in: ---[ end trace 6a95a3a73a02a177 ]--- RIP: 0010:mutex_can_spin_on_owner kernel/locking/mutex.c:620 [inline] RIP: 0010:mutex_optimistic_spin kernel/locking/mutex.c:664 [inline] RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:976 [inline] RIP: 0010:__mutex_lock+0x18e/0xc50 kernel/locking/mutex.c:1117 Code: 42 80 3c 28 00 74 08 48 89 df e8 6d 5c 26 fd 4c 8b 3b 49 83 e7 f8 0f 84 93 00 00 00 4c 89 e9 4d 8d 6f 2c 4c 89 e8 48 c1 e8 03 <0f> b6 04 08 84 c0 0f 85 64 08 00 00 41 83 7d 00 00 0f 84 24 01 00 RSP: 0018:ffffc90000f8f4e0 EFLAGS: 00010207 RAX: 0f0605e6a6af060a RBX: ffff888126a2fc40 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888126a2fc40 RBP: ffffc90000f8f600 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed1024d45f88 R11: 1ffff11024d45f88 R12: ffff888127dbcf00 R13: 78302f3535783054 R14: 0000000000000003 R15: 78302f3535783028 FS: 00007fad2537a6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2a1385 CR3: 00000001249e0000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) 5: 74 08 je 0xf 7: 48 89 df mov %rbx,%rdi a: e8 6d 5c 26 fd call 0xfd265c7c f: 4c 8b 3b mov (%rbx),%r15 12: 49 83 e7 f8 and $0xfffffffffffffff8,%r15 16: 0f 84 93 00 00 00 je 0xaf 1c: 4c 89 e9 mov %r13,%rcx 1f: 4d 8d 6f 2c lea 0x2c(%r15),%r13 23: 4c 89 e8 mov %r13,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 64 08 00 00 jne 0x89a 36: 41 83 7d 00 00 cmpl $0x0,0x0(%r13) 3b: 0f .byte 0xf 3c: 84 24 01 test %ah,(%rcx,%rax,1)