SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=17511 comm=syz-executor.4
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=17534 comm=syz-executor.1
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=17525 comm=syz-executor.5
===============================
[ INFO: suspicious RCU usage. ]
4.9.141+ #1 Not tainted
-------------------------------
net/ipv6/ip6_fib.c:1471 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 0
4 locks held by syz-executor.5/17538:
 #0:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff812629ba>] lockdep_copy_map include/linux/lockdep.h:165 [inline]
 #0:  (((&net->ipv6.ip6_fib_timer))){+.-...}, at: [<ffffffff812629ba>] call_timer_fn+0xda/0x6e0 kernel/time/timer.c:1309
 #1:  (&(&net->ipv6.fib6_gc_lock)->rlock){+.-...}, at: [<ffffffff826ef615>] spin_lock_bh include/linux/spinlock.h:307 [inline]
 #1:  (&(&net->ipv6.fib6_gc_lock)->rlock){+.-...}, at: [<ffffffff826ef615>] fib6_run_gc+0xa5/0x2c0 net/ipv6/ip6_fib.c:1816
 #2:  (rcu_read_lock){......}, at: [<ffffffff826e6c70>] __fib6_clean_all+0x0/0x220 net/ipv6/ip6_fib.c:1703
 #3:  (&tb->tb6_lock){++--..}, at: [<ffffffff826e6d50>] __fib6_clean_all+0xe0/0x220 net/ipv6/ip6_fib.c:1717

stack backtrace:
CPU: 0 PID: 17538 Comm: syz-executor.5 Not tainted 4.9.141+ #1
 ffff8801db6078c8 ffffffff81b42e79 ffff8801d0ce0000 0000000000000000
 0000000000000002 ffffffff82cc2480 ffffed003b6c0f67 ffff8801db6078f8
 ffffffff813fe948 ffff8801c76d68c0 ffff8801db607ae8 ffff8801c76d68c0
Call Trace:
 <IRQ> [  397.956404]  [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 <IRQ> [  397.956404]  [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff813fe948>] lockdep_rcu_suspicious.cold.32+0x110/0x141 kernel/locking/lockdep.c:4455
 [<ffffffff826eed80>] fib6_del+0x810/0xb10 net/ipv6/ip6_fib.c:1470
 [<ffffffff826ef2a0>] fib6_clean_node+0x220/0x4c0 net/ipv6/ip6_fib.c:1657
 [<ffffffff826e6545>] fib6_walk_continue+0x3e5/0x640 net/ipv6/ip6_fib.c:1583
 [<ffffffff826e6b01>] fib6_walk+0x91/0xf0 net/ipv6/ip6_fib.c:1628
 [<ffffffff826e6c33>] fib6_clean_tree+0xd3/0x110 net/ipv6/ip6_fib.c:1702
 [<ffffffff826e6d69>] __fib6_clean_all+0xf9/0x220 net/ipv6/ip6_fib.c:1718
 [<ffffffff826ef687>] fib6_clean_all net/ipv6/ip6_fib.c:1729 [inline]
 [<ffffffff826ef687>] fib6_run_gc+0x117/0x2c0 net/ipv6/ip6_fib.c:1826
 [<ffffffff826ef84c>] fib6_gc_timer_cb+0x1c/0x20 net/ipv6/ip6_fib.c:1841
 [<ffffffff81262a43>] call_timer_fn+0x163/0x6e0 kernel/time/timer.c:1319
 [<ffffffff812631f4>] expire_timers+0x234/0x580 kernel/time/timer.c:1359
 [<ffffffff81263748>] __run_timers kernel/time/timer.c:1674 [inline]
 [<ffffffff81263748>] run_timer_softirq+0x208/0x5e0 kernel/time/timer.c:1687
 [<ffffffff8281cb9e>] __do_softirq+0x20e/0x964 kernel/softirq.c:288
 [<ffffffff810efdbc>] invoke_softirq kernel/softirq.c:368 [inline]
 [<ffffffff810efdbc>] irq_exit+0x11c/0x150 kernel/softirq.c:409
 [<ffffffff8281b771>] exiting_irq arch/x86/include/asm/apic.h:669 [inline]
 [<ffffffff8281b771>] smp_apic_timer_interrupt+0x81/0xb0 arch/x86/kernel/apic/apic.c:962
 [<ffffffff8281902d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> [  398.222116]  [<ffffffff81243c4b>] ? debug_lockdep_rcu_enabled+0x3b/0x90 kernel/rcu/update.c:264
 [<ffffffff811679ab>] ___might_sleep+0x1b/0x260 kernel/sched/core.c:7954
 [<ffffffff81167c85>] __might_sleep+0x95/0x1a0 kernel/sched/core.c:7945
 [<ffffffff8149502f>] __might_fault+0xaf/0x1d0 mm/memory.c:4020
 [<ffffffff822a5cd3>] __sys_recvmmsg+0x283/0x6f0 net/socket.c:2255
 [<ffffffff822a62d9>] SYSC_recvmmsg net/socket.c:2325 [inline]
 [<ffffffff822a62d9>] SyS_recvmmsg+0x199/0x1c0 net/socket.c:2314
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
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tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
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tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
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SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=17591 comm=syz-executor.1
tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
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tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
¦ÕfË÷aŸ¨c–?a°Tý$�›ª›‚DHPížé"AÛ8˜™$—
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tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
¦ÕfË÷aŸ¨c–?a°Tý$�›ª›‚DHPížé"AÛ8˜™$—
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tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
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tmpfs: Bad mount option 9ÝrŸTpë 1`0Ì~éDZhñÕŒxý>ø†&-߈.µq’K´PßU×ñi¶.&6¾rɆYªãÁõs)ˆÉ+1+j§L%DA<32‰
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