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stall in inet_rtm_newaddr (2) From: syzbot To: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, hdanton@sina.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam01 X-Stat-Signature: z3rx5oic3aqpr49jsdstky9ybxiuyogx X-Rspam-User: X-Rspamd-Queue-Id: 01F8E8000E X-HE-Tag: 1760168484-792479 X-HE-Meta: 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 JMZ/5/jX 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 Bn2DwqMA Vil2XQIo7XFhwfHnyjas93aCdUS/d+C95Oj1/Lroac76DfceQuuL2XYJM97SlA3v+qg3jI5PVctHpjmBmBvc91dxP3udm6iqXH93IRkAHQDoDRSQWPh8tji0x78VE+LxSFIUBBCwWSEyubI6g1/sFIaQMrzRR0SkAWk2ipnXYN7XdY84OBxk2A9FbN3LoegXc3EmEHJBanfolXoQghHjyZa9uwCUKMJk3Y0sf1zFnnwrszl0QgP7JP+U42EtDi7vNOxNk70sdfin8sBGq4bv7TX2ffKbz0/bmXU8m7G6KRYMMd6F2Jht+fpKgXlcL0dqDYLoM/Vt7t+Z2tmT8+9UsjJ8kJtFWoeZpiVlGNK0GHnVrNiHfFh1xwCR84zVuVHe X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: syzbot has found a reproducer for the following issue on: HEAD commit: 18a7e218cfcd Merge tag 'net-6.18-rc1' of git://git.kernel... git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=12504dcd980000 kernel config: https://syzkaller.appspot.com/x/.config?x=61ab7fa743df0ec1 dashboard link: https://syzkaller.appspot.com/bug?extid=51cd74c5dfeafd65e488 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14d2a542580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=142149e2580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7a01e6dce97e/disk-18a7e218.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/5e1b7e41427f/vmlinux-18a7e218.xz kernel image: https://storage.googleapis.com/syzbot-assets/69b558601209/bzImage-18a7e218.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+51cd74c5dfeafd65e488@syzkaller.appspotmail.com sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 GPs behind) idle=7754/1/0x4000000000000000 softirq=15464/15465 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=11321, q=371 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5948 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:rb_insert_color_cached include/linux/rbtree.h:113 [inline] RIP: 0010:rb_add_cached include/linux/rbtree.h:183 [inline] RIP: 0010:timerqueue_add+0x1a8/0x200 lib/timerqueue.c:40 Code: e7 31 f6 e8 6a 0c de f6 42 80 3c 2b 00 74 08 4c 89 f7 e8 7b 0a de f6 4d 89 26 4d 8d 7e 08 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 ff e8 5e 0a de f6 4d 89 27 4d 85 e4 40 0f 95 c5 eb 07 RSP: 0018:ffffc90000007cf0 EFLAGS: 00000046 RAX: 1ffff110170c4f83 RBX: 1ffff110170c4f82 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88805de72358 RBP: 0000000000000000 R08: ffff88805de72357 R09: 0000000000000000 R10: ffff88805de72340 R11: ffffed100bbce46b R12: ffff88805de72340 R13: dffffc0000000000 R14: ffff8880b8627c10 R15: ffff8880b8627c18 FS: 000055557c657500(0000) GS:ffff888125d0f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000600 CR3: 000000002ee76000 CR4: 00000000003526f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1794 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_vcpu_is_preempted arch/x86/include/asm/paravirt.h:579 [inline] RIP: 0010:vcpu_is_preempted arch/x86/include/asm/qspinlock.h:63 [inline] RIP: 0010:owner_on_cpu include/linux/sched.h:2282 [inline] RIP: 0010:mutex_spin_on_owner+0x189/0x360 kernel/locking/mutex.c:361 Code: b6 04 30 84 c0 0f 85 59 01 00 00 48 8b 44 24 08 8b 18 48 8b 44 24 48 42 80 3c 30 00 74 0c 48 c7 c7 90 8c fa 8d e8 a7 cd 88 00 <48> 83 3d ff 27 5e 0c 00 0f 84 b9 01 00 00 48 89 df e8 41 e0 d5 ff RSP: 0018:ffffc900034c7428 EFLAGS: 00000246 RAX: 1ffffffff1bf5192 RBX: 0000000000000001 RCX: ffffffff819c6588 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f4df8a0 RBP: 1ffffffff1e9bf14 R08: ffffffff8f4df8a7 R09: 1ffffffff1e9bf14 R10: dffffc0000000000 R11: fffffbfff1e9bf15 R12: ffffffff8f4df8a0 R13: ffffffff8f4df8f0 R14: dffffc0000000000 R15: ffff8880267a9e40 mutex_optimistic_spin kernel/locking/mutex.c:464 [inline] __mutex_lock_common kernel/locking/mutex.c:602 [inline] __mutex_lock+0x311/0x1350 kernel/locking/mutex.c:760 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6954 netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 __sys_sendto+0x3bd/0x520 net/socket.c:2244 __do_sys_sendto net/socket.c:2251 [inline] __se_sys_sendto net/socket.c:2247 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2247 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faade790d5c Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b RSP: 002b:00007ffdd2e3b670 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007faadf514620 RCX: 00007faade790d5c RDX: 0000000000000028 RSI: 00007faadf514670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffdd2e3b6c4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007faadf514670 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g11321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=4286 rcu: rcu_preempt kthread starved for 10500 jiffies! g11321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 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:I stack:27224 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.