=============================
WARNING: suspicious RCU usage
4.15.0-rc8+ #1 Not tainted
-----------------------------
./include/linux/rcupdate.h:302 Illegal context switch in RCU read-side critical section!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor7/7702:
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] map_get_next_key kernel/bpf/syscall.c:836 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] SYSC_bpf kernel/bpf/syscall.c:1881 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] SyS_bpf+0x1105/0x4860 kernel/bpf/syscall.c:1846

stack backtrace:
CPU: 0 PID: 7702 Comm: syz-executor7 Not tainted 4.15.0-rc8+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4585
 rcu_preempt_sleep_check include/linux/rcupdate.h:301 [inline]
 ___might_sleep+0x385/0x470 kernel/sched/core.c:6025
 __might_sleep+0x95/0x190 kernel/sched/core.c:6013
 slab_pre_alloc_hook mm/slab.h:419 [inline]
 slab_alloc mm/slab.c:3368 [inline]
 __do_kmalloc mm/slab.c:3706 [inline]
 __kmalloc+0x2c5/0x760 mm/slab.c:3717
 kmalloc include/linux/slab.h:504 [inline]
 trie_get_next_key+0x517/0xf10 kernel/bpf/lpm_trie.c:626
 map_get_next_key kernel/bpf/syscall.c:842 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1881 [inline]
 SyS_bpf+0x11b4/0x4860 kernel/bpf/syscall.c:1846
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ef9
RSP: 002b:00007f5fd41d8c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f5fd41d9700 RCX: 0000000000452ef9
RDX: 0000000000000018 RSI: 0000000020013fe8 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 00007ffc6510a73f R14: 00007f5fd41d99c0 R15: 0000000000000000
BUG: sleeping function called from invalid context at mm/slab.h:419
in_atomic(): 1, irqs_disabled(): 0, pid: 7702, name: syz-executor7
1 lock held by syz-executor7/7702:
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] map_get_next_key kernel/bpf/syscall.c:836 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] SYSC_bpf kernel/bpf/syscall.c:1881 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] SyS_bpf+0x1105/0x4860 kernel/bpf/syscall.c:1846
CPU: 0 PID: 7702 Comm: syz-executor7 Not tainted 4.15.0-rc8+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060
 __might_sleep+0x95/0x190 kernel/sched/core.c:6013
 slab_pre_alloc_hook mm/slab.h:419 [inline]
 slab_alloc mm/slab.c:3368 [inline]
 __do_kmalloc mm/slab.c:3706 [inline]
 __kmalloc+0x2c5/0x760 mm/slab.c:3717
 kmalloc include/linux/slab.h:504 [inline]
 trie_get_next_key+0x517/0xf10 kernel/bpf/lpm_trie.c:626
 map_get_next_key kernel/bpf/syscall.c:842 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1881 [inline]
 SyS_bpf+0x11b4/0x4860 kernel/bpf/syscall.c:1846
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ef9
RSP: 002b:00007f5fd41d8c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f5fd41d9700 RCX: 0000000000452ef9
RDX: 0000000000000018 RSI: 0000000020013fe8 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 00007ffc6510a73f R14: 00007f5fd41d99c0 R15: 0000000000000000
hugetlbfs: Bad mount option: "9"
hugetlbfs: Bad mount option: "9"
audit: type=1400 audit(1516661238.475:20): avc:  denied  { create } for  pid=8345 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1
tmpfs: No value for mount option 'b�^�<S[��'
audit: type=1400 audit(1516661241.585:21): avc:  denied  { create } for  pid=8947 comm="syz-executor0" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_iscsi_socket permissive=1
audit: type=1400 audit(1516661242.181:22): avc:  denied  { create } for  pid=9082 comm="syz-executor4" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_fib_lookup_socket permissive=1
cgroup: cgroup2: unknown option ""
cgroup: cgroup2: unknown option ""
overlayfs: missing 'lowerdir'
overlayfs: missing 'lowerdir'
BUG: sleeping function called from invalid context at mm/slab.h:419
in_atomic(): 1, irqs_disabled(): 0, pid: 9345, name: syz-executor3
1 lock held by syz-executor3/9345:
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] map_get_next_key kernel/bpf/syscall.c:836 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] SYSC_bpf kernel/bpf/syscall.c:1881 [inline]
 #0:  (rcu_read_lock){....}, at: [<00000000c42de659>] SyS_bpf+0x1105/0x4860 kernel/bpf/syscall.c:1846
CPU: 1 PID: 9345 Comm: syz-executor3 Tainted: G        W        4.15.0-rc8+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060
 __might_sleep+0x95/0x190 kernel/sched/core.c:6013
 slab_pre_alloc_hook mm/slab.h:419 [inline]
 slab_alloc mm/slab.c:3368 [inline]
 __do_kmalloc mm/slab.c:3706 [inline]
 __kmalloc+0x2c5/0x760 mm/slab.c:3717
 kmalloc include/linux/slab.h:504 [inline]
 trie_get_next_key+0x517/0xf10 kernel/bpf/lpm_trie.c:626
 map_get_next_key kernel/bpf/syscall.c:842 [inline]
 SYSC_bpf kernel/bpf/syscall.c:1881 [inline]
 SyS_bpf+0x11b4/0x4860 kernel/bpf/syscall.c:1846
 entry_SYSCALL_64_fastpath+0x29/0xa0
RIP: 0033:0x452ef9
RSP: 002b:00007f2c297b0c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ef9
RDX: 0000000000000018 RSI: 0000000020013fe8 RDI: 0000000000000004
RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ef6a0
R13: 00000000ffffffff R14: 00007f2c297b16d4 R15: 0000000000000000