================================================================== BUG: KASAN: slab-use-after-free in __raw_spin_lock_irq include/linux/spinlock_api_smp.h:165 [inline] BUG: KASAN: slab-use-after-free in _raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:189 Read of size 1 at addr ffff0000c9aca818 by task syz.6.1119/11173 CPU: 0 UID: 0 PID: 11173 Comm: syz.6.1119 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_address_description+0xb0/0x238 mm/kasan/report.c:378 print_report+0x68/0x84 mm/kasan/report.c:482 kasan_report+0x8c/0xc4 mm/kasan/report.c:595 __kasan_check_byte+0x3c/0x54 mm/kasan/common.c:585 kasan_check_byte include/linux/kasan.h:402 [inline] lock_acquire+0xa4/0x320 kernel/locking/lockdep.c:5916 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:165 [inline] _raw_spin_lock_irq+0x58/0x70 kernel/locking/spinlock.c:189 spin_lock_irq include/linux/spinlock.h:377 [inline] gadget_dev_open+0x50/0x1c4 drivers/usb/gadget/legacy/inode.c:1929 do_dentry_open+0x5c4/0xfbc fs/open.c:996 vfs_open+0x44/0x2dc fs/open.c:1101 do_open fs/namei.c:4866 [inline] path_openat+0x1084/0x18f0 fs/namei.c:5029 do_file_open+0x1c8/0x2e8 fs/namei.c:5058 do_sys_openat2+0x114/0x1e8 fs/open.c:1417 do_sys_open+0xb0/0xe0 fs/open.c:1423 __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __arm64_sys_openat+0xa8/0xc4 fs/open.c:1434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 Allocated by task 5665: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:570 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0x9c/0xb4 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_noprof+0x34c/0x6c8 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] neigh_alloc net/core/neighbour.c:518 [inline] ___neigh_create+0x618/0x20a0 net/core/neighbour.c:652 __neigh_create+0x80/0xa4 net/core/neighbour.c:740 ip6_finish_output2+0xc50/0x1338 net/ipv6/ip6_output.c:130 __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline] ip6_finish_output+0x230/0x618 net/ipv6/ip6_output.c:221 NF_HOOK_COND include/linux/netfilter.h:314 [inline] ip6_output+0x2d0/0x528 net/ipv6/ip6_output.c:248 dst_output include/net/dst.h:471 [inline] NF_HOOK+0x14c/0x464 include/linux/netfilter.h:325 mld_sendpack+0x72c/0xd34 net/ipv6/mcast.c:1890 mld_send_initial_cr+0x238/0x2fc net/ipv6/mcast.c:2308 ipv6_mc_dad_complete+0x74/0x170 net/ipv6/mcast.c:2316 addrconf_dad_completed+0x530/0x9e4 net/ipv6/addrconf.c:4376 addrconf_dad_work+0x8a4/0xfe8 net/ipv6/addrconf.c:-1 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0x91c/0x1250 kernel/workqueue.c:3479 worker_thread+0x798/0xbd0 kernel/workqueue.c:3560 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 Freed by task 15: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x54/0x6c mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] __rcu_free_sheaf_prepare+0x130/0x2b4 mm/slub.c:3009 rcu_free_sheaf+0x28/0xd8 mm/slub.c:6061 rcu_do_batch kernel/rcu/tree.c:2650 [inline] rcu_core+0x790/0xfbc kernel/rcu/tree.c:2919 rcu_core_si+0x10/0x1c kernel/rcu/tree.c:2936 handle_softirqs+0x324/0xcbc kernel/softirq.c:645 run_ksoftirqd+0x70/0xbc kernel/softirq.c:1099 smpboot_thread_fn+0x4e4/0x97c kernel/smpboot.c:160 kthread+0x304/0x3d4 kernel/kthread.c:436 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:854 The buggy address belongs to the object at ffff0000c9aca800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 24 bytes inside of freed 1024-byte region [ffff0000c9aca800, ffff0000c9acac00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff0000c9acb800 pfn:0x109ac8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x5ffc00000000240(workingset|head|node=0|zone=2|lastcpupid=0x7ff) page_type: f5(slab) raw: 05ffc00000000240 ffff0000c0001dc0 fffffdffc364ca10 fffffdffc3604810 raw: ffff0000c9acb800 000000000010000b 00000000f5000000 0000000000000000 head: 05ffc00000000240 ffff0000c0001dc0 fffffdffc364ca10 fffffdffc3604810 head: ffff0000c9acb800 000000000010000b 00000000f5000000 0000000000000000 head: 05ffc00000000003 fffffdffc326b201 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000c9aca700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000c9aca780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff0000c9aca800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000c9aca880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000c9aca900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ------------[ cut here ]------------ UBSAN: array-index-out-of-bounds in kernel/locking/qspinlock.h:68:9 index 12602 is out of range for type 'unsigned long[8]' CPU: 0 UID: 0 PID: 11173 Comm: syz.6.1119 Tainted: G B L syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 ubsan_epilogue+0x14/0x48 lib/ubsan.c:233 __ubsan_handle_out_of_bounds+0xd0/0xf8 lib/ubsan.c:455 decode_tail kernel/locking/qspinlock.h:68 [inline] queued_spin_lock_slowpath+0x834/0xb5c kernel/locking/qspinlock.c:307 queued_spin_lock include/asm-generic/qspinlock.h:115 [inline] do_raw_spin_lock+0x21c/0x2d0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:166 [inline] _raw_spin_lock_irq+0x60/0x70 kernel/locking/spinlock.c:189 spin_lock_irq include/linux/spinlock.h:377 [inline] gadget_dev_open+0x50/0x1c4 drivers/usb/gadget/legacy/inode.c:1929 do_dentry_open+0x5c4/0xfbc fs/open.c:996 vfs_open+0x44/0x2dc fs/open.c:1101 do_open fs/namei.c:4866 [inline] path_openat+0x1084/0x18f0 fs/namei.c:5029 do_file_open+0x1c8/0x2e8 fs/namei.c:5058 do_sys_openat2+0x114/0x1e8 fs/open.c:1417 do_sys_open+0xb0/0xe0 fs/open.c:1423 __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __arm64_sys_openat+0xa8/0xc4 fs/open.c:1434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 ---[ end trace ]--- Unable to handle kernel paging request at virtual address ffff8000897ba150 KASAN: probably user-memory-access in range [0x000000044bdd0a80-0x000000044bdd0a87] Mem abort info: ESR = 0x0000000096000047 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x07: level 3 translation fault Data abort info: ISV = 0, ISS = 0x00000047, ISS2 = 0x00000000 CM = 0, WnR = 1, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0 swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000219508000 [ffff8000897ba150] pgd=0000000000000000, p4d=100000021f82f003, pud=100000021f830003, pmd=100000021f834003, pte=0000000000000000 Internal error: Oops: 0000000096000047 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 11173 Comm: syz.6.1119 Tainted: G B L syzkaller #0 PREEMPT Tainted: [B]=BAD_PAGE, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/23/2026 pstate: 834000c5 (Nzcv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : queued_spin_lock_slowpath+0x544/0xb5c kernel/locking/qspinlock.c:310 lr : decode_tail kernel/locking/qspinlock.h:68 [inline] lr : queued_spin_lock_slowpath+0x834/0xb5c kernel/locking/qspinlock.c:307 sp : ffff8000934f7620 x29: ffff8000934f76c0 x28: 1fffe000359ed028 x27: 1fffe0001a744002 x26: ffff0001acf68148 x25: ffff8000897ba150 x24: dfff800000000000 x23: ffff70001269eec8 x22: 1fffe00019359500 x21: ffff0001acf68140 x20: ffff0000d3a20010 x19: ffff0000c9aca800 x18: 0000000000000000 x17: 363a682e6b636f6c x16: 0000000000000001 x15: 0000000000000000 x14: 0000000000001fc5 x13: 0000000000000001 x12: 0000000000000004 x11: ffff700011604e68 x10: ffff8000897ba140 x9 : ffff8000897ba150 x8 : 0000000000000000 x7 : 0000000000000001 x6 : ffff800080484084 x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff8000802f41d4 x2 : 0000000000000002 x1 : 0000000000000004 x0 : ffff0001acf68148 Call trace: queued_spin_lock_slowpath+0x544/0xb5c kernel/locking/qspinlock.c:313 (P) queued_spin_lock include/asm-generic/qspinlock.h:115 [inline] do_raw_spin_lock+0x21c/0x2d0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:166 [inline] _raw_spin_lock_irq+0x60/0x70 kernel/locking/spinlock.c:189 spin_lock_irq include/linux/spinlock.h:377 [inline] gadget_dev_open+0x50/0x1c4 drivers/usb/gadget/legacy/inode.c:1929 do_dentry_open+0x5c4/0xfbc fs/open.c:996 vfs_open+0x44/0x2dc fs/open.c:1101 do_open fs/namei.c:4866 [inline] path_openat+0x1084/0x18f0 fs/namei.c:5029 do_file_open+0x1c8/0x2e8 fs/namei.c:5058 do_sys_openat2+0x114/0x1e8 fs/open.c:1417 do_sys_open+0xb0/0xe0 fs/open.c:1423 __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __arm64_sys_openat+0xa8/0xc4 fs/open.c:1434 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606 Code: aa1903e0 968adf85 910022a0 52800081 (f9000335) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: aa1903e0 mov x0, x25 4: 968adf85 bl 0xfffffffffa2b7e18 8: 910022a0 add x0, x21, #0x8 c: 52800081 mov w1, #0x4 // #4 * 10: f9000335 str x21, [x25] <-- trapping instruction