linux/net
Vadim Lomovtsev eebe53e87f net: sunrpc: svcsock: fix NULL-pointer exception
While running nfs/connectathon tests kernel NULL-pointer exception
has been observed due to races in svcsock.c.

Race is appear when kernel accepts connection by kernel_accept
(which creates new socket) and start queuing ingress packets
to new socket. This happens in ksoftirq context which could run
concurrently on a different core while new socket setup is not done yet.

The fix is to re-order socket user data init sequence and add
write/read barrier calls to be sure that we got proper values
for callback pointers before actually calling them.

Test results: nfs/connectathon reports '0' failed tests for about 200+ iterations.

Crash log:
---<-snip->---
[ 6708.638984] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 6708.647093] pgd = ffff0000094e0000
[ 6708.650497] [00000000] *pgd=0000010ffff90003, *pud=0000010ffff90003, *pmd=0000010ffff80003, *pte=0000000000000000
[ 6708.660761] Internal error: Oops: 86000005 [#1] SMP
[ 6708.665630] Modules linked in: nfsv3 nfnetlink_queue nfnetlink_log nfnetlink rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache overlay xt_CONNSECMARK xt_SECMARK xt_conntrack iptable_security ip_tables ah4 xfrm4_mode_transport sctp tun binfmt_misc ext4 jbd2 mbcache loop tcp_diag udp_diag inet_diag rpcrdma ib_isert iscsi_target_mod ib_iser rdma_cm iw_cm libiscsi scsi_transport_iscsi ib_srpt target_core_mod ib_srp scsi_transport_srp ib_ipoib ib_ucm ib_uverbs ib_umad ib_cm ib_core nls_koi8_u nls_cp932 ts_kmp nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack vfat fat ghash_ce sha2_ce sha1_ce cavium_rng_vf i2c_thunderx sg thunderx_edac i2c_smbus edac_core cavium_rng nfsd auth_rpcgss nfs_acl lockd grace sunrpc xfs libcrc32c nicvf nicpf ast i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops
[ 6708.736446]  ttm drm i2c_core thunder_bgx thunder_xcv mdio_thunder mdio_cavium dm_mirror dm_region_hash dm_log dm_mod [last unloaded: stap_3c300909c5b3f46dcacd49aab3334af_87021]
[ 6708.752275] CPU: 84 PID: 0 Comm: swapper/84 Tainted: G        W  OE   4.11.0-4.el7.aarch64 #1
[ 6708.760787] Hardware name: www.cavium.com CRB-2S/CRB-2S, BIOS 0.3 Mar 13 2017
[ 6708.767910] task: ffff810006842e80 task.stack: ffff81000689c000
[ 6708.773822] PC is at 0x0
[ 6708.776739] LR is at svc_data_ready+0x38/0x88 [sunrpc]
[ 6708.781866] pc : [<0000000000000000>] lr : [<ffff0000029d7378>] pstate: 60000145
[ 6708.789248] sp : ffff810ffbad3900
[ 6708.792551] x29: ffff810ffbad3900 x28: ffff000008c73d58
[ 6708.797853] x27: 0000000000000000 x26: ffff81000bbe1e00
[ 6708.803156] x25: 0000000000000020 x24: ffff800f7410bf28
[ 6708.808458] x23: ffff000008c63000 x22: ffff000008c63000
[ 6708.813760] x21: ffff800f7410bf28 x20: ffff81000bbe1e00
[ 6708.819063] x19: ffff810012412400 x18: 00000000d82a9df2
[ 6708.824365] x17: 0000000000000000 x16: 0000000000000000
[ 6708.829667] x15: 0000000000000000 x14: 0000000000000001
[ 6708.834969] x13: 0000000000000000 x12: 722e736f622e676e
[ 6708.840271] x11: 00000000f814dd99 x10: 0000000000000000
[ 6708.845573] x9 : 7374687225000000 x8 : 0000000000000000
[ 6708.850875] x7 : 0000000000000000 x6 : 0000000000000000
[ 6708.856177] x5 : 0000000000000028 x4 : 0000000000000000
[ 6708.861479] x3 : 0000000000000000 x2 : 00000000e5000000
[ 6708.866781] x1 : 0000000000000000 x0 : ffff81000bbe1e00
[ 6708.872084]
[ 6708.873565] Process swapper/84 (pid: 0, stack limit = 0xffff81000689c000)
[ 6708.880341] Stack: (0xffff810ffbad3900 to 0xffff8100068a0000)
[ 6708.886075] Call trace:
[ 6708.888513] Exception stack(0xffff810ffbad3710 to 0xffff810ffbad3840)
[ 6708.894942] 3700:                                   ffff810012412400 0001000000000000
[ 6708.902759] 3720: ffff810ffbad3900 0000000000000000 0000000060000145 ffff800f79300000
[ 6708.910577] 3740: ffff000009274d00 00000000000003ea 0000000000000015 ffff000008c63000
[ 6708.918395] 3760: ffff810ffbad3830 ffff800f79300000 000000000000004d 0000000000000000
[ 6708.926212] 3780: ffff810ffbad3890 ffff0000080f88dc ffff800f79300000 000000000000004d
[ 6708.934030] 37a0: ffff800f7930093c ffff000008c63000 0000000000000000 0000000000000140
[ 6708.941848] 37c0: ffff000008c2c000 0000000000040b00 ffff81000bbe1e00 0000000000000000
[ 6708.949665] 37e0: 00000000e5000000 0000000000000000 0000000000000000 0000000000000028
[ 6708.957483] 3800: 0000000000000000 0000000000000000 0000000000000000 7374687225000000
[ 6708.965300] 3820: 0000000000000000 00000000f814dd99 722e736f622e676e 0000000000000000
[ 6708.973117] [<          (null)>]           (null)
[ 6708.977824] [<ffff0000086f9fa4>] tcp_data_queue+0x754/0xc5c
[ 6708.983386] [<ffff0000086fa64c>] tcp_rcv_established+0x1a0/0x67c
[ 6708.989384] [<ffff000008704120>] tcp_v4_do_rcv+0x15c/0x22c
[ 6708.994858] [<ffff000008707418>] tcp_v4_rcv+0xaf0/0xb58
[ 6709.000077] [<ffff0000086df784>] ip_local_deliver_finish+0x10c/0x254
[ 6709.006419] [<ffff0000086dfea4>] ip_local_deliver+0xf0/0xfc
[ 6709.011980] [<ffff0000086dfad4>] ip_rcv_finish+0x208/0x3a4
[ 6709.017454] [<ffff0000086e018c>] ip_rcv+0x2dc/0x3c8
[ 6709.022328] [<ffff000008692fc8>] __netif_receive_skb_core+0x2f8/0xa0c
[ 6709.028758] [<ffff000008696068>] __netif_receive_skb+0x38/0x84
[ 6709.034580] [<ffff00000869611c>] netif_receive_skb_internal+0x68/0xdc
[ 6709.041010] [<ffff000008696bc0>] napi_gro_receive+0xcc/0x1a8
[ 6709.046690] [<ffff0000014b0fc4>] nicvf_cq_intr_handler+0x59c/0x730 [nicvf]
[ 6709.053559] [<ffff0000014b1380>] nicvf_poll+0x38/0xb8 [nicvf]
[ 6709.059295] [<ffff000008697a6c>] net_rx_action+0x2f8/0x464
[ 6709.064771] [<ffff000008081824>] __do_softirq+0x11c/0x308
[ 6709.070164] [<ffff0000080d14e4>] irq_exit+0x12c/0x174
[ 6709.075206] [<ffff00000813101c>] __handle_domain_irq+0x78/0xc4
[ 6709.081027] [<ffff000008081608>] gic_handle_irq+0x94/0x190
[ 6709.086501] Exception stack(0xffff81000689fdf0 to 0xffff81000689ff20)
[ 6709.092929] fde0:                                   0000810ff2ec0000 ffff000008c10000
[ 6709.100747] fe00: ffff000008c70ef4 0000000000000001 0000000000000000 ffff810ffbad9b18
[ 6709.108565] fe20: ffff810ffbad9c70 ffff8100169d3800 ffff810006843ab0 ffff81000689fe80
[ 6709.116382] fe40: 0000000000000bd0 0000ffffdf979cd0 183f5913da192500 0000ffff8a254ce4
[ 6709.124200] fe60: 0000ffff8a254b78 0000aaab10339808 0000000000000000 0000ffff8a0c2a50
[ 6709.132018] fe80: 0000ffffdf979b10 ffff000008d6d450 ffff000008c10000 ffff000008d6d000
[ 6709.139836] fea0: 0000000000000054 ffff000008cd3dbc 0000000000000000 0000000000000000
[ 6709.147653] fec0: 0000000000000000 0000000000000000 0000000000000000 ffff81000689ff20
[ 6709.155471] fee0: ffff000008085240 ffff81000689ff20 ffff000008085244 0000000060000145
[ 6709.163289] ff00: ffff81000689ff10 ffff00000813f1e4 ffffffffffffffff ffff00000813f238
[ 6709.171107] [<ffff000008082eb4>] el1_irq+0xb4/0x140
[ 6709.175976] [<ffff000008085244>] arch_cpu_idle+0x44/0x11c
[ 6709.181368] [<ffff0000087bf3b8>] default_idle_call+0x20/0x30
[ 6709.187020] [<ffff000008116d50>] do_idle+0x158/0x1e4
[ 6709.191973] [<ffff000008116ff4>] cpu_startup_entry+0x2c/0x30
[ 6709.197624] [<ffff00000808e7cc>] secondary_start_kernel+0x13c/0x160
[ 6709.203878] [<0000000001bc71c4>] 0x1bc71c4
[ 6709.207967] Code: bad PC value
[ 6709.211061] SMP: stopping secondary CPUs
[ 6709.218830] Starting crashdump kernel...
[ 6709.222749] Bye!
---<-snip>---

Signed-off-by: Vadim Lomovtsev <vlomovts@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-08-24 18:11:28 -04:00
..
6lowpan 6lowpan: Don't set IFF_NO_QUEUE 2017-04-12 22:02:40 +02:00
9p Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
802 net: introduce __skb_put_[zero, data, u8] 2017-06-20 13:30:14 -04:00
8021q net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
appletalk networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
atm net, atm: convert eg_cache_entry.use from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
ax25 net, ax25: convert ax25_cb.refcount from atomic_t to refcount_t 2017-07-04 22:35:19 +01:00
batman-adv networking: make skb_put & friends return void pointers 2017-06-16 11:48:39 -04:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
bpf bpf: Align packet data properly in program testing framework. 2017-05-02 11:46:28 -04:00
bridge bridge: mdb: fix leak on complete_info ptr on fail path 2017-07-11 20:01:39 -07:00
caif net: convert sock.sk_wmem_alloc from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
can networking: introduce and use skb_put_data() 2017-06-16 11:48:37 -04:00
ceph Add wait_for_random_bytes() and get_random_*_wait() functions so that 2017-07-15 12:44:02 -07:00
core Add wait_for_random_bytes() and get_random_*_wait() functions so that 2017-07-15 12:44:02 -07:00
dcb dcb: enforce minimum length on IEEE_APPS attribute 2017-05-21 13:42:33 -04:00
dccp net: convert sk_buff.users from atomic_t to refcount_t 2017-07-01 07:39:07 -07:00
decnet net, decnet: convert dn_fib_info.fib_clntref from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
dns_resolver Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-03-03 10:16:38 -08:00
dsa net: manual clean code which call skb_put_[data:zero] 2017-06-20 13:30:15 -04:00
ethernet networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
hsr net: add netlink_ext_ack argument to rtnl_link_ops.newlink 2017-06-26 23:13:21 -04:00
ieee802154 net: add netlink_ext_ack argument to rtnl_link_ops.validate 2017-06-26 23:13:22 -04:00
ife
ipv4 Add wait_for_random_bytes() and get_random_*_wait() functions so that 2017-07-15 12:44:02 -07:00
ipv6 net: ipv6: Compare lwstate in detecting duplicate nexthops 2017-07-06 10:48:01 +01:00
ipx net, ipx: convert ipx_route.refcnt from atomic_t to refcount_t 2017-07-04 22:35:17 +01:00
irda Merge branch 'work.memdup_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-05 16:05:24 -07:00
iucv iucv: Convert sk_wmem_alloc accesses to refcount_t. 2017-07-03 02:31:22 -07:00
kcm net: convert sock.sk_wmem_alloc from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
key net, xfrm: convert xfrm_policy.refcnt from atomic_t to refcount_t 2017-07-04 22:35:18 +01:00
l2tp net, l2tp: convert l2tp_session.ref_count from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
l3mdev
lapb net, lapb: convert lapb_cb.refcnt from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
llc net, llc: convert llc_sap.refcnt from atomic_t to refcount_t 2017-07-04 22:35:15 +01:00
mac80211 net: manual clean code which call skb_put_[data:zero] 2017-06-20 13:30:15 -04:00
mac802154 net: Fix inconsistent teardown and release of private netdev state. 2017-06-07 15:53:24 -04:00
mpls mpls: fix uninitialized in_label var warning in mpls_getroute 2017-07-08 11:26:41 +01:00
ncsi networking: make skb_push & __skb_push return void pointers 2017-06-16 11:48:40 -04:00
netfilter net/netfilter/x_tables.c: use kvmalloc() in xt_alloc_table_info() 2017-07-12 16:26:02 -07:00
netlabel netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
netlink net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
netrom net, netrom: convert nr_node.refcount from atomic_t to refcount_t 2017-07-04 22:35:17 +01:00
nfc NFC: Add sockaddr length checks before accessing sa_family in bind handlers 2017-06-23 00:38:31 +02:00
openvswitch openvswitch: fix mis-ordered comment lines for ovs_skb_cb 2017-07-03 05:54:00 -07:00
packet net: convert packet_fanout.sk_ref from atomic_t to refcount_t 2017-07-01 07:39:09 -07:00
phonet net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
psample networking: make skb_put & friends return void pointers 2017-06-16 11:48:39 -04:00
qrtr networking: make skb_put & friends return void pointers 2017-06-16 11:48:39 -04:00
rds rds: tcp: use sock_create_lite() to create the accept socket 2017-07-08 11:16:16 +01:00
rfkill net: rfkill: gpio: Switch to devm_acpi_dev_add_driver_gpios() 2017-06-13 11:07:51 +02:00
rose net: Work around lockdep limitation in sockets that use sockets 2017-03-09 18:23:27 -08:00
rxrpc net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
sched mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful semantic 2017-07-12 16:26:03 -07:00
sctp sctp: set the value of flowi6_oif to sk_bound_dev_if to make sctp_v6_get_dst to find the correct route entry. 2017-07-06 11:39:54 +01:00
smc net/smc: Add warning about remote memory exposure 2017-05-16 14:49:43 -04:00
strparser strparser: destroy workqueue on module exit 2017-03-03 20:43:26 -08:00
sunrpc net: sunrpc: svcsock: fix NULL-pointer exception 2017-08-24 18:11:28 -04:00
switchdev net: switchdev: Change notifier chain to be atomic 2017-06-08 14:16:24 -04:00
tipc net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
tls TLS: Fix length check in do_tls_getsockopt_tx() 2017-07-06 10:58:19 +01:00
unix Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-07-05 12:31:59 -07:00
vmw_vsock net: manual clean code which call skb_put_[data:zero] 2017-06-20 13:30:15 -04:00
wimax
wireless netlink validation fixes for nl80211 2017-07-07 11:35:55 +01:00
x25 net, x25: convert x25_neigh.refcnt from atomic_t to refcount_t 2017-07-04 22:35:18 +01:00
xfrm net, xfrm: convert sec_path.refcnt from atomic_t to refcount_t 2017-07-04 22:35:18 +01:00
compat.c get_compat_bpf_fprog(): don't copyin field-by-field 2017-07-04 13:14:34 -04:00
Kconfig tls: kernel TLS support 2017-06-15 12:12:40 -04:00
Makefile tls: kernel TLS support 2017-06-15 12:12:40 -04:00
socket.c Merge branch 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:06:17 -07:00
sysctl_net.c sysctl: Remove dead register_sysctl_root 2017-04-16 23:42:49 -05:00