Eric Dumazet b1c17a9a35 flow_dissector: disable preemption around BPF calls ... Various things in eBPF really require us to disable preemption before running an eBPF program. syzbot reported : BUG: assuming atomic context at net/core/flow_dissector.c:737 in_atomic(): 0, irqs_disabled(): 0, pid: 24710, name: syz-executor.3 2 locks held by syz-executor.3/24710: #0: 00000000e81a4bf1 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x168e/0x3ff0 drivers/net/tun.c:1850 #1: 00000000254afebd (rcu_read_lock){....}, at: __skb_flow_dissect+0x1e1/0x4bb0 net/core/flow_dissector.c:822 CPU: 1 PID: 24710 Comm: syz-executor.3 Not tainted 5.1.0+ #6 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 Fixes: d58e468b11 ("flow_dissector: implements flow dissector BPF hook") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Petar Penkov <ppenkov@google.com> Cc: Stanislav Fomichev <sdf@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2019-05-13 09:53:42 -07:00
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bpf_sk_storage.c
datagram.c
datagram.h
dev_addr_lists.c
dev_ioctl.c
dev.c
devlink.c
drop_monitor.c
dst_cache.c
dst.c
ethtool.c
failover.c
fib_notifier.c
fib_rules.c
filter.c
flow_dissector.c
flow_offload.c
gen_estimator.c
gen_stats.c
gro_cells.c
hwbm.c
link_watch.c
lwt_bpf.c
lwtunnel.c
Makefile
neighbour.c
net_namespace.c
net-procfs.c
net-sysfs.c
net-sysfs.h
net-traces.c
netclassid_cgroup.c
netevent.c
netpoll.c
netprio_cgroup.c
page_pool.c
pktgen.c
ptp_classifier.c
request_sock.c
rtnetlink.c
scm.c
secure_seq.c
skbuff.c
skmsg.c
sock_diag.c
sock_map.c
sock_reuseport.c
sock.c
stream.c
sysctl_net_core.c
timestamping.c
tso.c
utils.c
xdp.c