BUG: assuming atomic context at net/core/flow_dissector.c:737
in_atomic(): 0, irqs_disabled(): 0, pid: 8535, name: syz-executor.2
2 locks held by syz-executor.2/8535:
 #0: 00000000cb8277f2 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x168e/0x3ff0 drivers/net/tun.c:1850
 #1: 0000000061fa3e82 (rcu_read_lock){....}, at: __skb_flow_dissect+0x1e1/0x4bb0 net/core/flow_dissector.c:822
CPU: 0 PID: 8535 Comm: syz-executor.2 Not tainted 5.1.0-next-20190510 #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 __cant_sleep kernel/sched/core.c:6165 [inline]
 __cant_sleep.cold+0xa3/0xbb kernel/sched/core.c:6142
 bpf_flow_dissect+0xfe/0x390 net/core/flow_dissector.c:737
 __skb_flow_dissect+0x362/0x4bb0 net/core/flow_dissector.c:853
 skb_flow_dissect_flow_keys_basic include/linux/skbuff.h:1322 [inline]
 skb_probe_transport_header include/linux/skbuff.h:2500 [inline]
 skb_probe_transport_header include/linux/skbuff.h:2493 [inline]
 tun_get_user+0x2cfe/0x3ff0 drivers/net/tun.c:1940
 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2037
 call_write_iter include/linux/fs.h:1872 [inline]
 do_iter_readv_writev+0x5fd/0x900 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:951
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015
 do_writev+0x15b/0x330 fs/read_write.c:1058
 __do_sys_writev fs/read_write.c:1131 [inline]
 __se_sys_writev fs/read_write.c:1128 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1128
 do_syscall_64+0x103/0x670 arch/x86/entry/common.c:298
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c61
Code: 75 14 b8 14 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 e4 b9 fb ff c3 48 83 ec 08 e8 1a 2d 00 00 48 89 04 24 b8 14 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 63 2d 00 00 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fefa02b4ba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000036d RCX: 0000000000458c61
RDX: 0000000000000001 RSI: 00007fefa02b4c00 RDI: 00000000000000f0
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 00007fefa02b59d0 R11: 0000000000000293 R12: 00007fefa02b56d4
R13: 00000000004c77d2 R14: 00000000004dd9d0 R15: 00000000ffffffff