============================= WARNING: suspicious RCU usage 4.14.101+ #14 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 4 locks held by udevd/17931: #0: (((&net->ipv6.ip6_fib_timer))){+.-.}, at: [] lockdep_copy_map include/linux/lockdep.h:174 [inline] #0: (((&net->ipv6.ip6_fib_timer))){+.-.}, at: [] call_timer_fn+0xc6/0x680 kernel/time/timer.c:1269 #1: (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [] spin_lock_bh include/linux/spinlock.h:322 [inline] #1: (&(&net->ipv6.fib6_gc_lock)->rlock){+.-.}, at: [] fib6_run_gc+0x93/0x2a0 net/ipv6/ip6_fib.c:1938 #2: (rcu_read_lock){....}, at: [] __fib6_clean_all+0x0/0x230 net/ipv6/ip6_fib.c:1823 #3: (&tb->tb6_lock){++--}, at: [] __fib6_clean_all+0xde/0x230 net/ipv6/ip6_fib.c:1837 stack backtrace: CPU: 1 PID: 17931 Comm: udevd Not tainted 4.14.101+ #14 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:rmqueue mm/page_alloc.c:2859 [inline] RIP: 0010:get_page_from_freelist+0x1695/0x1d60 mm/page_alloc.c:3178 RSP: 0018:ffff88817aa07828 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000007 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000246 RBP: ffffea0006d20400 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff8d220500 R14: dffffc0000000000 R15: ffffea0006d20200 __alloc_pages_nodemask+0x20f/0x22e0 mm/page_alloc.c:4190 __alloc_pages include/linux/gfp.h:461 [inline] __alloc_pages_node include/linux/gfp.h:474 [inline] alloc_pages_node include/linux/gfp.h:488 [inline] alloc_slab_page mm/slub.c:1437 [inline] allocate_slab mm/slub.c:1580 [inline] new_slab+0xa2/0x480 mm/slub.c:1651 audit: type=1326 audit(2000000095.280:117): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26185 comm="syz-executor.2" exe="/root/syz-executor.2" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000095.310:118): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26186 comm="syz-executor.1" exe="/root/syz-executor.1" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000095.360:119): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26196 comm="syz-executor.5" exe="/root/syz-executor.5" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000095.540:120): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26219 comm="syz-executor.3" exe="/root/syz-executor.3" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000095.580:121): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26221 comm="syz-executor.0" exe="/root/syz-executor.0" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000096.060:122): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26185 comm="syz-executor.2" exe="/root/syz-executor.2" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000096.090:123): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26186 comm="syz-executor.1" exe="/root/syz-executor.1" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000096.160:124): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26196 comm="syz-executor.5" exe="/root/syz-executor.5" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 kauditd_printk_skb: 2 callbacks suppressed audit: type=1326 audit(2000000096.340:127): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26219 comm="syz-executor.3" exe="/root/syz-executor.3" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000096.380:128): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26221 comm="syz-executor.0" exe="/root/syz-executor.0" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000096.990:129): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26235 comm="syz-executor.1" exe="/root/syz-executor.1" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 audit: type=1326 audit(2000000097.020:130): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 pid=26241 comm="syz-executor.2" exe="/root/syz-executor.2" sig=31 arch=c000003e syscall=228 compat=0 ip=0x45ac8a code=0xffff0000 ip6_vti0: Invalid MTU 0 requested, hw min 1280 ip6_vti0: Invalid MTU 0 requested, hw min 1280