============================= WARNING: suspicious RCU usage 4.14.96+ #19 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1590 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 5 locks held by syz-executor4/27709: #0: (sk_lock-AF_INET6){+.+.}, at: [] lock_sock include/net/sock.h:1456 [inline] #0: (sk_lock-AF_INET6){+.+.}, at: [] do_tcp_setsockopt.isra.0+0x10c/0x1bf0 net/ipv4/tcp.c:2537 #1: (((&net->ipv6.ip6_fib_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #1: (((&net->ipv6.ip6_fib_timer))){+.-.}, at: [] call_timer_fn+0xc6/0x680 kernel/time/timer.c:1269 #2: (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [] spin_lock_bh include/linux/spinlock.h:322 [inline] #2: (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [] fib6_run_gc+0x93/0x2a0 net/ipv6/ip6_fib.c:1938 #3: (rcu_read_lock){....}, at: [] __fib6_clean_all+0x0/0x230 net/ipv6/ip6_fib.c:1823 #4: (&tb->tb6_lock){++--}, at: [] __fib6_clean_all+0xde/0x230 net/ipv6/ip6_fib.c:1837 stack backtrace: CPU: 1 PID: 27709 Comm: syz-executor4 Not tainted 4.14.96+ #19 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 fib6_del+0x8c2/0xbe0 net/ipv6/ip6_fib.c:1590 fib6_clean_node+0x270/0x440 net/ipv6/ip6_fib.c:1777 fib6_walk_continue+0x3a5/0x5f0 net/ipv6/ip6_fib.c:1703 fib6_walk+0x8d/0xe0 net/ipv6/ip6_fib.c:1748 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:1822 __fib6_clean_all+0xf5/0x230 net/ipv6/ip6_fib.c:1838 fib6_clean_all net/ipv6/ip6_fib.c:1849 [inline] fib6_run_gc+0x104/0x2a0 net/ipv6/ip6_fib.c:1947 call_timer_fn+0x14a/0x680 kernel/time/timer.c:1279 expire_timers+0x216/0x4b0 kernel/time/timer.c:1318 __run_timers kernel/time/timer.c:1634 [inline] run_timer_softirq+0x1eb/0x5d0 kernel/time/timer.c:1647 __do_softirq+0x234/0x9ca kernel/softirq.c:288 invoke_softirq kernel/softirq.c:368 [inline] irq_exit+0x114/0x150 kernel/softirq.c:409 exiting_irq arch/x86/include/asm/apic.h:648 [inline] smp_apic_timer_interrupt+0x185/0x620 arch/x86/kernel/apic/apic.c:1064 apic_timer_interrupt+0x84/0x90 arch/x86/entry/entry_64.S:787 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:778 [inline] RIP: 0010:lock_is_held_type+0xfb/0x150 kernel/locking/lockdep.c:4031 RSP: 0018:ffff8881a6dcfc48 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000007 RBX: 0000000000000246 RCX: 1ffffffff6f82328 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000246 RBP: ffff8881a5519780 R08: 0000000000000000 R09: ffffed1034db9fa8 R10: ffffed1034db9fa7 R11: ffff8881a6dcfd3f R12: 0000000000000000 R13: 000000000000000a R14: 0000000000000000 R15: ffff8881c0f9343c lock_is_held include/linux/lockdep.h:437 [inline] ___might_sleep+0x1c6/0x280 kernel/sched/core.c:6076 binder: 27838:27849 unknown command 1074061397 binder: 27838:27849 ioctl c0306201 20000300 returned -22 binder: 27838:27849 unknown command 1074061397 binder: 27838:27849 ioctl c0306201 20000300 returned -22 selinux_nlmsg_perm: 24 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=37196 sclass=netlink_route_socket pig=27873 comm=syz-executor1 FAT-fs (loop1): bogus number of reserved sectors FAT-fs (loop1): Can't find a valid FAT filesystem FAT-fs (loop3): bogus number of reserved sectors FAT-fs (loop3): Can't find a valid FAT filesystem FAT-fs (loop3): bogus number of reserved sectors FAT-fs (loop3): Can't find a valid FAT filesystem netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 188 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 188 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 12 bytes leftover after parsing attributes in process `syz-executor3'.