Warning: Permanently added '10.128.1.35' (ED25519) to the list of known hosts. executing program [ 51.820653][ T4164] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 52.002663][ T4166] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 52.185387][ T4168] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 52.358773][ T4170] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 52.531892][ T4172] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 52.714276][ T4174] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 52.886777][ T4176] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 53.069614][ T4178] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 53.252647][ T4180] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 53.435378][ T4182] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 56.895678][ T4222] tbf_change: 19 callbacks suppressed [ 56.895689][ T4222] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 57.083016][ T4224] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 57.265634][ T4226] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 57.438422][ T4228] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 57.621145][ T4230] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 57.793671][ T4232] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 57.966813][ T4234] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 58.149456][ T4236] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! [ 58.166651][ T4236] [ 58.169108][ T4236] ============================= [ 58.173972][ T4236] WARNING: suspicious RCU usage [ 58.178808][ T4236] 5.15.179-syzkaller #0 Not tainted [ 58.184115][ T4236] ----------------------------- [ 58.189023][ T4236] net/sched/sch_api.c:304 suspicious rcu_dereference_protected() usage! [ 58.197354][ T4236] [ 58.197354][ T4236] other info that might help us debug this: [ 58.197354][ T4236] [ 58.207586][ T4236] [ 58.207586][ T4236] rcu_scheduler_active = 2, debug_locks = 1 [ 58.215661][ T4236] 5 locks held by syz-executor332/4236: [ 58.221214][ T4236] #0: ffffffff8cb1f4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 [ 58.230600][ T4236] #1: ffffffff8cb1f540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 [ 58.240261][ T4236] #2: ffffffff8cb1f540 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x9/0x30 [ 58.249880][ T4236] #3: ffff8880219d4108 (&sch->q.lock){+...}-{2:2}, at: __dev_queue_xmit+0xc1f/0x32b0 [ 58.259552][ T4236] #4: ffffffff8cb1f4e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 [ 58.268874][ T4236] [ 58.268874][ T4236] stack backtrace: [ 58.274783][ T4236] CPU: 0 PID: 4236 Comm: syz-executor332 Not tainted 5.15.179-syzkaller #0 [ 58.283794][ T4236] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 [ 58.293834][ T4236] Call Trace: [ 58.297095][ T4236] [ 58.300017][ T4236] dump_stack_lvl+0x1e3/0x2d0 [ 58.304691][ T4236] ? io_uring_drop_tctx_refs+0x1a0/0x1a0 [ 58.310315][ T4236] ? lockdep_rcu_suspicious+0x158/0x1c0 [ 58.315851][ T4236] qdisc_lookup+0xa8/0x630 [ 58.320277][ T4236] qdisc_tree_reduce_backlog+0x212/0x4f0 [ 58.325901][ T4236] fq_codel_enqueue+0x1139/0x15e0 [ 58.330923][ T4236] ? INET_ECN_set_ce+0x970/0x970 [ 58.335857][ T4236] ? read_lock_is_recursive+0x10/0x10 [ 58.341214][ T4236] tbf_enqueue+0x35d/0x6f0 [ 58.345625][ T4236] dev_qdisc_enqueue+0x47/0x240 [ 58.350461][ T4236] ? __dev_queue_xmit+0xcba/0x32b0 [ 58.355559][ T4236] __dev_queue_xmit+0xe32/0x32b0 [ 58.360491][ T4236] ? dev_queue_xmit+0x20/0x20 [ 58.365176][ T4236] ? lockdep_hardirqs_on_prepare+0x438/0x7a0 [ 58.371134][ T4236] ? print_irqtrace_events+0x210/0x210 [ 58.376587][ T4236] ? __ipv6_neigh_lookup_noref+0x59b/0x730 [ 58.382381][ T4236] ? ip6_finish_output2+0xcbf/0x15a0 [ 58.387655][ T4236] ip6_finish_output2+0xead/0x15a0 [ 58.392755][ T4236] ? __ip6_finish_output+0x7d0/0x7d0 [ 58.398026][ T4236] ? __ip6_finish_output+0x645/0x7d0 [ 58.403306][ T4236] ip6_send_skb+0x1af/0x390 [ 58.407814][ T4236] udp_v6_send_skb+0xac4/0x1470 [ 58.412657][ T4236] udpv6_sendmsg+0x22ab/0x31d0 [ 58.417425][ T4236] ? ip_skb_dst_mtu+0x980/0x980 [ 58.422262][ T4236] ? udp_v6_early_demux+0xf30/0xf30 [ 58.427462][ T4236] ? aa_sk_perm+0x8fc/0xa30 [ 58.431960][ T4236] ? sock_rps_record_flow+0x19/0x3c0 [ 58.437231][ T4236] ? inet_send_prepare+0x56/0x250 [ 58.442239][ T4236] ? inet6_compat_ioctl+0x560/0x560 [ 58.447424][ T4236] ____sys_sendmsg+0x59e/0x8f0 [ 58.452170][ T4236] ? iovec_from_user+0x5d/0x390 [ 58.457013][ T4236] ? __sys_sendmsg_sock+0x30/0x30 [ 58.462036][ T4236] ___sys_sendmsg+0x252/0x2e0 [ 58.466713][ T4236] ? __sys_sendmsg+0x260/0x260 [ 58.471486][ T4236] ? __might_fault+0xb4/0x110 [ 58.476149][ T4236] __sys_sendmmsg+0x2bf/0x560 [ 58.480828][ T4236] ? __ia32_sys_sendmsg+0x80/0x80 [ 58.485859][ T4236] ? __lock_acquire+0x1ff0/0x1ff0 [ 58.490887][ T4236] ? __sys_connect+0x18a/0x410 [ 58.495659][ T4236] ? print_irqtrace_events+0x210/0x210 [ 58.501116][ T4236] ? vtime_user_exit+0x2d1/0x400 [ 58.506046][ T4236] ? syscall_enter_from_user_mode+0x2e/0x240 [ 58.512014][ T4236] __x64_sys_sendmmsg+0x9c/0xb0 [ 58.516849][ T4236] do_syscall_64+0x3b/0xb0 [ 58.521247][ T4236] ? clear_bhb_loop+0x15/0x70 [ 58.525911][ T4236] entry_SYSCALL_64_after_hwframe+0x66/0xd0 [ 58.531802][ T4236] RIP: 0033:0x7f454ce31869 [ 58.536205][ T4236] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 [ 58.555792][ T4236] RSP: 002b:00007f454cdf2218 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 58.564195][ T4236] RAX: ffffffffffffffda RBX: 00007f454cebb348 RCX: 00007f454ce31869 [ 58.572154][ T4236] RDX: 00000000000004ff RSI: 00002000000092c0 RDI: 0000000000000009 [ 58.580235][ T4236] RBP: 00007f454cebb340 R08: 0000000000000000 R09: 0000000000000000 [ 58.588194][ T4236] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f454ce88074 executing program [ 58.596149][ T4236] R13: 00002000000002c8 R14: 00002000000002c0 R15: 00002000000092c0 [ 58.604110][ T4236] [ 58.625675][ T4238] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 58.798461][ T4240] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 61.953577][ T4300] tbf_change: 29 callbacks suppressed [ 61.953591][ T4300] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program [ 62.019242][ T4302] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 62.080829][ T4304] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! [ 62.142045][ T4306] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program [ 62.213928][ T4308] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 62.275483][ T4310] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 62.336565][ T4312] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 62.397860][ T4314] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 62.459286][ T4316] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 62.520543][ T4318] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 66.960974][ T4468] tbf_change: 74 callbacks suppressed [ 66.960985][ T4468] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 67.037233][ T4470] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program [ 67.108576][ T4472] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 67.170064][ T4474] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 67.231498][ T4476] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 67.292676][ T4478] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 67.353844][ T4480] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program [ 67.416073][ T4482] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! [ 67.476528][ T4484] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program [ 67.548035][ T4486] sch_tbf: burst 4398 is lower than device lo mtu (65550) ! executing program executing program executing program executing program executing program executing program executing program executing program executing program