================================================================== 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 ffff8881073e3440 by task syz.9.6920/24415 CPU: 1 PID: 24415 Comm: syz.9.6920 Not tainted 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: 0033:0x7fe630dd2510 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:00007fe62f83bb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe630dd2510 RDX: 0000000000000000 RSI: 00007fe62f83bc10 RDI: 00000000ffffff9c RBP: 00007fe62f83bc10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007fe63101b038 R14: 00007fe63101afa0 R15: 00007fff9a3f1028 Allocated by task 21275: 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] fib6_info_alloc+0x34/0xe0 net/ipv6/ip6_fib.c:154 ip6_route_info_create+0x4d2/0x1490 net/ipv6/route.c:3673 addrconf_f6i_alloc+0x154/0x360 net/ipv6/route.c:4472 ipv6_add_addr+0x40b/0xd40 net/ipv6/addrconf.c:1120 inet6_addr_add+0x44c/0x950 net/ipv6/addrconf.c:3017 inet6_rtm_newaddr+0x684/0x930 net/ipv6/addrconf.c:4961 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] __sys_sendto+0x41d/0x580 net/socket.c:2006 __do_sys_sendto net/socket.c:2018 [inline] __se_sys_sendto net/socket.c:2014 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:2014 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 24344: 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 fib6_info_destroy_rcu+0x171/0x1c0 net/ipv6/ip6_fib.c:177 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 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 __call_rcu kernel/rcu/tree.c:2980 [inline] call_rcu+0x10e/0x1050 kernel/rcu/tree.c:3054 fib6_info_release include/net/ip6_fib.h:346 [inline] __ip6_del_rt+0xf5/0x150 net/ipv6/route.c:3796 ip6_del_rt+0xb0/0xf0 net/ipv6/route.c:3807 __ipv6_ifa_notify+0x81b/0xdb0 net/ipv6/addrconf.c:6189 addrconf_ifdown+0xd5c/0x1800 net/ipv6/addrconf.c:3912 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_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 rtnl_group_changelink net/core/rtnetlink.c:3251 [inline] __rtnl_newlink net/core/rtnetlink.c:3420 [inline] rtnl_newlink+0xd32/0x1640 net/core/rtnetlink.c:3530 rtnetlink_rcv_msg+0x9db/0xb90 net/core/rtnetlink.c:5610 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2503 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5628 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1340 netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1914 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg net/socket.c:2466 [inline] __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb 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 put_css_set_locked+0x9b7/0x9f0 kernel/cgroup/cgroup.c:980 put_css_set kernel/cgroup/cgroup-internal.h:210 [inline] cgroup_free+0x68/0x80 kernel/cgroup/cgroup.c:6438 __put_task_struct+0xb4/0x420 kernel/fork.c:777 put_task_struct include/linux/sched/task.h:143 [inline] delayed_put_task_struct+0x6f/0x1a0 kernel/exit.c:221 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748 __do_softirq+0x255/0x563 kernel/softirq.c:309 The buggy address belongs to the object at ffff8881073e3400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 64 bytes inside of 512-byte region [ffff8881073e3400, ffff8881073e3600) The buggy address belongs to the page: page:ffffea00041cf800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8881073e2000 pfn:0x1073e0 head:ffffea00041cf800 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 ffffea0004788f08 ffffea00045b9308 ffff888100043080 raw: ffff8881073e2000 0000000000100008 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 275, ts 21603848964, free_ts 21602667669 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] new_dir fs/proc/proc_sysctl.c:958 [inline] get_subdir fs/proc/proc_sysctl.c:1003 [inline] __register_sysctl_table+0xa38/0x1250 fs/proc/proc_sysctl.c:1352 register_net_sysctl+0x2c/0x40 net/sysctl_net.c:121 __devinet_sysctl_register+0x2c4/0x390 net/ipv4/devinet.c:2598 devinet_sysctl_register+0x169/0x1e0 net/ipv4/devinet.c:2638 inetdev_init+0x273/0x480 net/ipv4/devinet.c:277 inetdev_event+0x1f8/0x1030 net/ipv4/devinet.c:1544 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+0x111/0x190 net/core/dev.c:2080 register_netdevice+0x1043/0x13c0 net/core/dev.c:10087 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_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629 free_the_page mm/page_alloc.c:5431 [inline] __free_pages+0xdd/0x380 mm/page_alloc.c:5440 __free_slab+0xcf/0x190 mm/slub.c:1899 free_slab mm/slub.c:1914 [inline] discard_slab mm/slub.c:1920 [inline] unfreeze_partials+0x15f/0x190 mm/slub.c:2415 put_cpu_partial+0xc1/0x180 mm/slub.c:2451 __slab_free+0x2c9/0x3a0 mm/slub.c:3100 do_slab_free mm/slub.c:3196 [inline] ___cache_free+0x111/0x130 mm/slub.c:3215 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157 qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xf0 mm/kasan/common.c:440 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc_trace+0x160/0x2e0 mm/slub.c:2977 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:664 [inline] inetdev_init+0x84/0x480 net/ipv4/devinet.c:259 inetdev_event+0x1f8/0x1030 net/ipv4/devinet.c:1544 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410 Memory state around the buggy address: ffff8881073e3300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881073e3380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8881073e3400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881073e3480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881073e3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== general protection fault, probably for non-canonical address 0xdffffc0000001024: 0000 [#1] PREEMPT SMP KASAN KASAN: probably user-memory-access in range [0x0000000000008120-0x0000000000008127] CPU: 0 PID: 24415 Comm: syz.9.6920 Tainted: G B 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 fd 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:ffffc90000d674e0 EFLAGS: 00010207 RAX: 0000000000001024 RBX: ffff8881073e3440 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881073e3440 RBP: ffffc90000d67600 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed1020e7c688 R11: 1ffff11020e7c688 R12: ffff88811ed92780 R13: 0000000000008124 R14: 0000000000000006 R15: 00000000000080f8 FS: 00007fe62f83c6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f71fddcad58 CR3: 0000000121526000 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: 0033:0x7fe630dd2510 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:00007fe62f83bb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe630dd2510 RDX: 0000000000000000 RSI: 00007fe62f83bc10 RDI: 00000000ffffff9c RBP: 00007fe62f83bc10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd R13: 00007fe63101b038 R14: 00007fe63101afa0 R15: 00007fff9a3f1028 Modules linked in: ---[ end trace 6e9ced5595fa4885 ]--- 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 fd 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:ffffc90000d674e0 EFLAGS: 00010207 RAX: 0000000000001024 RBX: ffff8881073e3440 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881073e3440 RBP: ffffc90000d67600 R08: fffffffffffffffb R09: 0000000000000007 R10: ffffed1020e7c688 R11: 1ffff11020e7c688 R12: ffff88811ed92780 R13: 0000000000008124 R14: 0000000000000006 R15: 00000000000080f8 FS: 00007fe62f83c6c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f71fddcad58 CR3: 0000000121526000 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 fd 5c 26 fd call 0xfd265d0c 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)