Taehee Yoo 0a5eca2c94 gtp: fix Illegal context switch in RCU read-side critical section. ... [ Upstream commit 3f167e1921865b379a9becf03828e7202c7b4917 ] ipv4_pdp_add() is called in RCU read-side critical section. So GFP_KERNEL should not be used in the function. This patch make ipv4_pdp_add() to use GFP_ATOMIC instead of GFP_KERNEL. Test commands: gtp-link add gtp1 & gtp-tunnel add gtp1 v1 100 200 1.1.1.1 2.2.2.2 Splat looks like: [ 130.618881] ============================= [ 130.626382] WARNING: suspicious RCU usage [ 130.626994] 5.2.0-rc6+ #50 Not tainted [ 130.627622] ----------------------------- [ 130.628223] ./include/linux/rcupdate.h:266 Illegal context switch in RCU read-side critical section! [ 130.629684] [ 130.629684] other info that might help us debug this: [ 130.629684] [ 130.631022] [ 130.631022] rcu_scheduler_active = 2, debug_locks = 1 [ 130.632136] 4 locks held by gtp-tunnel/1025: [ 130.632925] #0: 000000002b93c8b7 (cb_lock){++++}, at: genl_rcv+0x15/0x40 [ 130.634159] #1: 00000000f17bc999 (genl_mutex){+.+.}, at: genl_rcv_msg+0xfb/0x130 [ 130.635487] #2: 00000000c644ed8e (rtnl_mutex){+.+.}, at: gtp_genl_new_pdp+0x18c/0x1150 [gtp] [ 130.636936] #3: 0000000007a1cde7 (rcu_read_lock){....}, at: gtp_genl_new_pdp+0x187/0x1150 [gtp] [ 130.638348] [ 130.638348] stack backtrace: [ 130.639062] CPU: 1 PID: 1025 Comm: gtp-tunnel Not tainted 5.2.0-rc6+ #50 [ 130.641318] Call Trace: [ 130.641707] dump_stack+0x7c/0xbb [ 130.642252] ___might_sleep+0x2c0/0x3b0 [ 130.642862] kmem_cache_alloc_trace+0x1cd/0x2b0 [ 130.643591] gtp_genl_new_pdp+0x6c5/0x1150 [gtp] [ 130.644371] genl_family_rcv_msg+0x63a/0x1030 [ 130.645074] ? mutex_lock_io_nested+0x1090/0x1090 [ 130.645845] ? genl_unregister_family+0x630/0x630 [ 130.646592] ? debug_show_all_locks+0x2d0/0x2d0 [ 130.647293] ? check_flags.part.40+0x440/0x440 [ 130.648099] genl_rcv_msg+0xa3/0x130 [ ... ] Fixes: 459aa660eb ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo <ap420073@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>		2019-07-26 09:14:17 +02:00
..
appletalk	net/appletalk: fix minor pointer leak to userspace in SIOCFINDIPDDPRT	2018-09-13 10:35:57 -07:00
arcnet
bonding	bonding: validate ip header before check IPPROTO_IGMP	2019-07-26 09:14:15 +02:00
caif
can	can: m_can: implement errata "Needless activation of MRAF irq"	2019-07-14 08:11:07 +02:00
dsa	net: dsa: mv88e6xxx: fix shift of FID bits in mv88e6185_g1_vtu_loadpurge()	2019-07-14 08:11:15 +02:00
ethernet	bnx2x: Prevent ptp_task to be rescheduled indefinitely	2019-07-26 09:14:15 +02:00
fddi
fjes
hamradio	net/hamradio/6pack: use mod_timer() to rearm timers	2019-01-09 17:38:32 +01:00
hippi
hyperv	hv_netvsc: Set probe mode to sync	2019-06-22 08:15:13 +02:00
ieee802154	net: ieee802154: fix missing checks for regmap_update_bits	2019-05-25 18:23:43 +02:00
ipvlan	net: ipvlan: Fix ipvlan device tso disabled while NETIF_F_IP_CSUM is set	2019-06-25 11:35:58 +08:00
netdevsim
phy	net: sfp: add mutex to prevent concurrent state checks	2019-07-26 09:14:05 +02:00
plip
ppp	ppp: mppe: Add softdep to arc4	2019-07-21 09:03:07 +02:00
slip	slip: make slhc_free() silently accept an error pointer	2019-05-02 09:58:56 +02:00
team	team: Always enable vlan tx offload	2019-07-03 13:14:47 +02:00
usb	net: usb: asix: init MAC address buffers	2019-07-26 09:14:15 +02:00
vmxnet3
wan	net/wan: fix a double free in x25_asy_open_tty()	2019-01-09 17:38:32 +01:00
wimax	wimax/i2400m: fix spelling mistake "not unitialized" -> "uninitialized"	2018-09-26 20:09:58 -07:00
wireless	iwlwifi: mvm: Drop large non sta frames	2019-07-26 09:14:14 +02:00
xen-netback	xen-netback: fix occasional leak of grant ref mappings under memory pressure	2019-03-10 07:17:19 +01:00
dummy.c
eql.c
geneve.c	geneve: correctly handle ipv6.disable module parameter	2019-03-10 07:17:17 +01:00
gtp.c	gtp: fix Illegal context switch in RCU read-side critical section.	2019-07-26 09:14:17 +02:00
ifb.c
Kconfig	gtp: change NET_UDP_TUNNEL dependency to select	2019-04-03 06:26:15 +02:00
LICENSE.SRC
loopback.c	net: loopback: clear skb->tstamp before netif_rx()	2018-11-13 11:08:20 -08:00
macsec.c
macvlan.c	macvlan: return correct error value	2018-12-21 14:15:20 +01:00
macvtap.c
Makefile	net: Always descend into dsa/	2019-05-25 18:23:19 +02:00
mdio.c
mii.c
net_failover.c	failover: Add missing check to validate 'slave_dev' in net_failover_slave_unregister	2018-11-13 11:08:28 -08:00
netconsole.c
nlmon.c
ntb_netdev.c
rionet.c	rapidio/rionet: do not free skb before reading its length	2018-12-05 19:31:59 +01:00
sb1000.c
Space.c
sungem_phy.c
tap.c
thunderbolt.c	net: thunderbolt: Unregister ThunderboltIP protocol handler when suspending	2019-06-15 11:54:07 +02:00
tun.c	tun: wake up waitqueues after IFF_UP is set	2019-07-03 13:14:48 +02:00
veth.c	veth: Orphan skb before GRO	2018-09-16 15:33:50 -07:00
virtio_net.c	virtio_net: Account for tx bytes and packets on sending xdp_frames	2019-02-12 19:47:23 +01:00
vrf.c	vrf: prevent adding upper devices	2019-04-03 06:26:18 +02:00
vsockmon.c
vxlan.c	vxlan: Don't call gro_cells_destroy() before device is unregistered	2019-04-03 06:26:18 +02:00
xen-netfront.c	xen/netfront: tolerate frags with no data	2019-01-09 17:38:34 +01:00