bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6456/1:b..l rcu: (detected by 0, t=10503 jiffies, g=15985, q=630 ncpus=2) task:syz.7.88 state:R running task stack:26056 pid:6456 ppid:5921 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_acquire+0x10/0x420 kernel/locking/lockdep.c:5722 Code: 05 dd 8b 9b 7e a9 00 ff ff 00 0f 95 c0 c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 <53> 48 83 e4 e0 48 81 ec e0 00 00 00 4c 89 4c 24 28 4c 89 44 24 30 RSP: 0018:ffffc90004f573d8 EFLAGS: 00000246 RAX: ffffffff81cfb49c RBX: 00002000007a0000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8d1320a0 RBP: ffffc90004f573f8 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc90004f575ac R11: fffff520009eaebe R12: ffff888022abbc00 R13: ffff88802b93e018 R14: 00002000007a0000 R15: ffffc90004f57458 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] __pte_offset_map+0x48/0x2c0 mm/pgtable-generic.c:287 pte_offset_map_nolock+0x44/0x130 mm/pgtable-generic.c:314 handle_pte_fault mm/memory.c:5033 [inline] __handle_mm_fault mm/memory.c:5188 [inline] handle_mm_fault+0xe37/0x4c00 mm/memory.c:5353 do_user_addr_fault+0x730/0x12c0 arch/x86/mm/fault.c:1371 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 29 f8 48 01 RSP: 0018:ffffc90004f57818 EFLAGS: 00050206 RAX: ffffffff8427e301 RBX: 0000000000008000 RCX: 0000000000000140 RDX: 0000000000000001 RSI: 00002000007a0000 RDI: ffff888030b07ec0 RBP: ffffc90004f57970 R08: ffff888030b07fff R09: 1ffff11006160fff R10: dffffc0000000000 R11: ffffed1006161000 R12: ffff888030b00000 R13: 0000200000798140 R14: ffffc90004f57c18 R15: 1ffff920009eaf83 copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:127 [inline] copyin lib/iov_iter.c:193 [inline] _copy_from_iter+0x24e/0x12e0 lib/iov_iter.c:390 copy_from_iter include/linux/uio.h:209 [inline] copy_from_iter_full include/linux/uio.h:216 [inline] skb_do_copy_data_nocache include/net/sock.h:2342 [inline] skb_copy_to_page_nocache include/net/sock.h:2368 [inline] kcm_sendmsg+0xd95/0x28b0 net/kcm/kcmsock.c:858 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x2df/0x420 net/socket.c:1160 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x46c/0x990 fs/read_write.c:584 ksys_write+0x150/0x260 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2e9579c819 RSP: 002b:00007f2e939f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2e95a15fa0 RCX: 00007f2e9579c819 RDX: 00000000fffffdef RSI: 0000200000000140 RDI: 0000000000000005 RBP: 00007f2e95832c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2e95a16038 R14: 00007f2e95a15fa0 R15: 00007fff5f6915b8 rcu: rcu_preempt kthread starved for 1604 jiffies! g15985 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27656 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6439 Comm: syz.5.81 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:asm_sysvec_apic_timer_interrupt+0x0/0x20 arch/x86/include/asm/idtentry.h:687 Code: 06 0b e6 ff e9 c1 04 00 00 90 f3 0f 1e fa 0f 01 ca fc 6a ff e8 c1 03 00 00 48 89 c4 48 89 e7 e8 26 0a e6 ff e9 a1 04 00 00 90 0f 1e fa 0f 01 ca fc 6a ff e8 a1 03 00 00 48 89 c4 48 89 e7 e8 RSP: 0018:ffffc900001efa68 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff8faf06d6 RCX: 0000000000000003 RDX: ffffffff813b4e99 RSI: ffffffff8cfa0820 RDI: 0000000000000000 RBP: ffffc900001efbb8 R08: ffff8880284c1e00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001efb68 R13: dffffc0000000000 R14: ffffc90005057f58 R15: ffffc900001efb9e FS: 00007f4b7efe46c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561950131a38 CR3: 000000007d6b8000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212 Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 8c ec 03 0d 48 89 de 5b e9 23 67 57 00 cc cc cc 0f 1e fa 48 8b 04 24 65 48 8b 0d e0 93 7c 7e 65 8b 15 e1 93 7c RSP: 0018:ffffc900001efa90 EFLAGS: 00000246 get_reg arch/x86/kernel/unwind_orc.c:455 [inline] unwind_next_frame+0x173b/0x2970 arch/x86/kernel/unwind_orc.c:643 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 skb_ext_maybe_cow net/core/skbuff.c:6664 [inline] skb_ext_add+0x1b3/0x8e0 net/core/skbuff.c:6738 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:165 [inline] br_nf_forward_ip+0xc6/0x1110 net/bridge/br_netfilter_hooks.c:709 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:259 [inline] NF_HOOK+0x23e/0x3e0 include/linux/netfilter.h:302 __br_forward+0x433/0x610 net/bridge/br_forward.c:115 br_handle_frame_finish+0x13c5/0x18f0 net/bridge/br_input.c:215 br_nf_hook_thresh+0x3cd/0x4a0 net/bridge/br_netfilter_hooks.c:1184 br_nf_pre_routing_finish_ipv6+0x9dc/0xd00 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x349/0x6b0 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x1245/0x14d0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xfab/0x3af0 net/core/dev.c:5528 __netif_receive_skb_one_core net/core/dev.c:5632 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5748 process_backlog+0x391/0x6f0 net/core/dev.c:6076 __napi_poll+0xc0/0x460 net/core/dev.c:6638 napi_poll net/core/dev.c:6705 [inline] net_rx_action+0x616/0xc40 net/core/dev.c:6841 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:schedule_debug kernel/sched/core.c:5938 [inline] RIP: 0010:__schedule+0x150/0x45a0 kernel/sched/core.c:6591 Code: 74 08 48 89 df e8 70 37 51 f7 48 8b 1b 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 57 37 51 f7 48 81 3b 9d 6e ac 57 <0f> 85 7d 16 00 00 45 85 ff 44 89 7c 24 6c 75 4c 48 8b 44 24 30 48 RSP: 0018:ffffc90005056dc0 EFLAGS: 00000246 RAX: 1ffff92000a0a000 RBX: ffffc90005050000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90005056f60 RBP: ffffc90005056fd0 R08: ffffc90005056f5f R09: 0000000000000000 R10: ffffc90005056f50 R11: fffff52000a0adec R12: 1ffff92000a0add8 R13: ffff8880b8f00000 R14: dffffc0000000000 R15: 0000000000000001 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6867 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6891 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 unwind_next_frame+0x200f/0x2970 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __set_page_owner+0x1d/0x60 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 __stack_depot_save+0x435/0x630 lib/stackdepot.c:410 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_set_track+0x5f/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 memcg_free_slab_cgroups mm/slab.h:463 [inline] unaccount_slab mm/slab.h:651 [inline] __free_slab+0xbe/0x260 mm/slub.c:2097 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 sk_prot_alloc+0x57/0x210 net/core/sock.c:2090 sk_alloc+0x3a/0x360 net/core/sock.c:2152 inet_create+0x7a0/0xfe0 net/ipv4/af_inet.c:325 __sock_create+0x4a6/0x940 net/socket.c:1570 sock_create net/socket.c:1626 [inline] __sys_socket_create net/socket.c:1663 [inline] __sys_socket+0xd7/0x1a0 net/socket.c:1714 __do_sys_socket net/socket.c:1728 [inline] __se_sys_socket net/socket.c:1726 [inline] __x64_sys_socket+0x7a/0x90 net/socket.c:1726 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4b7e19c819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4b7efe4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f4b7e415fa0 RCX: 00007f4b7e19c819 RDX: 0000000000000084 RSI: 0000000000000005 RDI: 0000000000000002 RBP: 00007f4b7e232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b7e416038 R14: 00007f4b7e415fa0 R15: 00007ffe1da8bce8 net_ratelimit: 6192 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) net_ratelimit: 13218 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:52:b9:48:ac:0a:d1, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)