================================================================== BUG: KASAN: double-free in inet_sock_destruct+0x597/0x830 net/ipv4/af_inet.c:159 Free of addr ffff8880784e9480 by task ksoftirqd/0/15 CPU: 0 UID: 0 PID: 15 Comm: ksoftirqd/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report_invalid_free+0xb8/0xe0 mm/kasan/report.c:557 check_slab_allocation+0xc3/0xf0 mm/kasan/common.c:234 kasan_slab_pre_free include/linux/kasan.h:198 [inline] slab_free_hook mm/slub.c:2485 [inline] slab_free mm/slub.c:6663 [inline] kfree+0x21d/0x6e0 mm/slub.c:6871 inet_sock_destruct+0x597/0x830 net/ipv4/af_inet.c:159 __sk_destruct+0x85/0xbc0 net/core/sock.c:2350 sk_destruct+0xc2/0xf0 net/core/sock.c:2412 __sk_free+0xf4/0x3e0 net/core/sock.c:2423 sk_free+0x6a/0x90 net/core/sock.c:2434 sock_put include/net/sock.h:1998 [inline] sctp_endpoint_destroy_rcu+0xd3/0x100 net/sctp/endpointola.c:197 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x15f0 kernel/rcu/tree.c:2857 handle_softirqs+0x219/0x950 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1063 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:1055 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 8564: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:397 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5652 [inline] __kmalloc_noprof+0x33d/0x910 mm/slub.c:5664 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ip_options_get+0xad/0x4a0 net/ipv4/ip_options.c:517 do_ip_setsockopt+0x27bd/0x3790 net/ipv4/ip_sockglue.c:1087 ip_setsockopt+0x59/0xf0 net/ipv4/ip_sockglue.c:1417 ipv6_setsockopt+0x155/0x170 net/ipv6/ipv6_sockglue.c:968 sctp_setsockopt+0x16c/0xb8c0 net/sctp/socket.c:4586 do_sock_setsockopt+0xf3/0x1d0 net/socket.c:2322 __sys_setsockopt+0x120/0x1a0 net/socket.c:2347 __do_sys_setsockopt net/socket.c:2353 [inline] __se_sys_setsockopt net/socket.c:2350 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2350 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5830: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6871 inet_sock_destruct+0x597/0x830 net/ipv4/af_inet.c:159 __sk_destruct+0x85/0xbc0 net/core/sock.c:2350 sk_destruct+0xc2/0xf0 net/core/sock.c:2412 __sk_free+0xf4/0x3e0 net/core/sock.c:2423 sk_free+0x6a/0x90 net/core/sock.c:2434 sock_put include/net/sock.h:1998 [inline] sctp_endpoint_destroy_rcu+0xd3/0x100 net/sctp/endpointola.c:197 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x15f0 kernel/rcu/tree.c:2857 handle_softirqs+0x219/0x950 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 The buggy address belongs to the object at ffff8880784e9480 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of 96-byte region [ffff8880784e9480, ffff8880784e94e0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880784e9c00 pfn:0x784e9 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88813ff26280 ffffea00009f9480 dead000000000002 raw: ffff8880784e9c00 000000000020001e 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1111, tgid 1111 (kworker/u8:8), ts 104861339268, free_ts 104803179039 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] __kmalloc_cache_noprof+0x485/0x800 mm/slub.c:5766 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] nsim_fib_event_schedule_work drivers/net/netdevsim/fib.c:990 [inline] nsim_fib_event_nb+0x1b6/0xec0 drivers/net/netdevsim/fib.c:1043 notifier_call_chain+0xbc/0x3e0 kernel/notifier.c:85 atomic_notifier_call_chain+0x71/0x1c0 kernel/notifier.c:223 call_fib_notifiers+0x33/0x70 net/core/fib_notifier.c:35 call_fib6_entry_notifiers net/ipv6/ip6_fib.c:409 [inline] fib6_add_rt2node+0x1cf2/0x3720 net/ipv6/ip6_fib.c:1248 fib6_add+0x628/0x1d90 net/ipv6/ip6_fib.c:1532 __ip6_ins_rt net/ipv6/route.c:1351 [inline] ip6_ins_rt+0xb5/0x110 net/ipv6/route.c:1361 __ipv6_ifa_notify+0xc9f/0xfd0 net/ipv6/addrconf.c:6283 page last free pid 23 tgid 23 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0x79c/0x15f0 kernel/rcu/tree.c:2857 handle_softirqs+0x219/0x950 kernel/softirq.c:622 run_ksoftirqd kernel/softirq.c:1063 [inline] run_ksoftirqd+0x3a/0x60 kernel/softirq.c:1055 smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff8880784e9380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8880784e9400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff8880784e9480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880784e9500: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff8880784e9580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================