linux/net
Chuck Lever e28b4fc652 svcrdma: Fix trace point use-after-free race
I hit this while testing nfsd-5.7 with kernel memory debugging
enabled on my server:

Mar 30 13:21:45 klimt kernel: BUG: unable to handle page fault for address: ffff8887e6c279a8
Mar 30 13:21:45 klimt kernel: #PF: supervisor read access in kernel mode
Mar 30 13:21:45 klimt kernel: #PF: error_code(0x0000) - not-present page
Mar 30 13:21:45 klimt kernel: PGD 3601067 P4D 3601067 PUD 87c519067 PMD 87c3e2067 PTE 800ffff8193d8060
Mar 30 13:21:45 klimt kernel: Oops: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
Mar 30 13:21:45 klimt kernel: CPU: 2 PID: 1933 Comm: nfsd Not tainted 5.6.0-rc6-00040-g881e87a3c6f9 #1591
Mar 30 13:21:45 klimt kernel: Hardware name: Supermicro Super Server/X10SRL-F, BIOS 1.0c 09/09/2015
Mar 30 13:21:45 klimt kernel: RIP: 0010:svc_rdma_post_chunk_ctxt+0xab/0x284 [rpcrdma]
Mar 30 13:21:45 klimt kernel: Code: c1 83 34 02 00 00 29 d0 85 c0 7e 72 48 8b bb a0 02 00 00 48 8d 54 24 08 4c 89 e6 48 8b 07 48 8b 40 20 e8 5a 5c 2b e1 41 89 c6 <8b> 45 20 89 44 24 04 8b 05 02 e9 01 00 85 c0 7e 33 e9 5e 01 00 00
Mar 30 13:21:45 klimt kernel: RSP: 0018:ffffc90000dfbdd8 EFLAGS: 00010286
Mar 30 13:21:45 klimt kernel: RAX: 0000000000000000 RBX: ffff8887db8db400 RCX: 0000000000000030
Mar 30 13:21:45 klimt kernel: RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000246
Mar 30 13:21:45 klimt kernel: RBP: ffff8887e6c27988 R08: 0000000000000000 R09: 0000000000000004
Mar 30 13:21:45 klimt kernel: R10: ffffc90000dfbdd8 R11: 00c068ef00000000 R12: ffff8887eb4e4a80
Mar 30 13:21:45 klimt kernel: R13: ffff8887db8db634 R14: 0000000000000000 R15: ffff8887fc931000
Mar 30 13:21:45 klimt kernel: FS:  0000000000000000(0000) GS:ffff88885bd00000(0000) knlGS:0000000000000000
Mar 30 13:21:45 klimt kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8 CR3: 000000081b72e002 CR4: 00000000001606e0
Mar 30 13:21:45 klimt kernel: Call Trace:
Mar 30 13:21:45 klimt kernel: ? svc_rdma_vec_to_sg+0x7f/0x7f [rpcrdma]
Mar 30 13:21:45 klimt kernel: svc_rdma_send_write_chunk+0x59/0xce [rpcrdma]
Mar 30 13:21:45 klimt kernel: svc_rdma_sendto+0xf9/0x3ae [rpcrdma]
Mar 30 13:21:45 klimt kernel: ? nfsd_destroy+0x51/0x51 [nfsd]
Mar 30 13:21:45 klimt kernel: svc_send+0x105/0x1e3 [sunrpc]
Mar 30 13:21:45 klimt kernel: nfsd+0xf2/0x149 [nfsd]
Mar 30 13:21:45 klimt kernel: kthread+0xf6/0xfb
Mar 30 13:21:45 klimt kernel: ? kthread_queue_delayed_work+0x74/0x74
Mar 30 13:21:45 klimt kernel: ret_from_fork+0x3a/0x50
Mar 30 13:21:45 klimt kernel: Modules linked in: ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm ocfs2_nodemanager ocfs2_stackglue ib_umad ib_ipoib mlx4_ib sb_edac x86_pkg_temp_thermal iTCO_wdt iTCO_vendor_support coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel glue_helper crypto_simd cryptd pcspkr rpcrdma i2c_i801 rdma_ucm lpc_ich mfd_core ib_iser rdma_cm iw_cm ib_cm mei_me raid0 libiscsi mei sg scsi_transport_iscsi ioatdma wmi ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter nfsd nfs_acl lockd auth_rpcgss grace sunrpc ip_tables xfs libcrc32c mlx4_en sd_mod sr_mod cdrom mlx4_core crc32c_intel igb nvme i2c_algo_bit ahci i2c_core libahci nvme_core dca libata t10_pi qedr dm_mirror dm_region_hash dm_log dm_mod dax qede qed crc8 ib_uverbs ib_core
Mar 30 13:21:45 klimt kernel: CR2: ffff8887e6c279a8
Mar 30 13:21:45 klimt kernel: ---[ end trace 87971d2ad3429424 ]---

It's absolutely not safe to use resources pointed to by the @send_wr
argument of ib_post_send() _after_ that function returns. Those
resources are typically freed by the Send completion handler, which
can run before ib_post_send() returns.

Thus the trace points currently around ib_post_send() in the
server's RPC/RDMA transport are a hazard, even when they are
disabled. Rearrange them so that they touch the Work Request only
_before_ ib_post_send() is invoked.

Fixes: bd2abef333 ("svcrdma: Trace key RDMA API events")
Fixes: 4201c74647 ("svcrdma: Introduce svc_rdma_send_ctxt")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-04-17 12:40:38 -04:00
..
6lowpan
9p 9pnet: allow making incomplete read requests 2020-03-27 09:29:56 +00:00
802 net: 802: psnap.c: Use built-in RCU list checking 2020-02-24 13:02:53 -08:00
8021q net: vlan: suppress "failed to kill vid" warnings 2020-02-17 14:30:54 -08:00
appletalk
atm proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ax25 net: Make sock protocol value checks more specific 2020-01-09 18:41:40 -08:00
batman-adv Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
bluetooth Bluetooth: L2CAP: Use DEFER_SETUP to group ECRED connections 2020-03-25 22:16:08 +01:00
bpf bpf: Fix build warning regarding missing prototypes 2020-03-28 18:13:18 +01:00
bpfilter SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
bridge net: bridge: vlan options: move the tunnel command to the nested attribute 2020-03-20 08:52:20 -07:00
caif net: caif: Add lockdep expression to RCU traversal primitive 2020-03-11 22:55:25 -07:00
can
ceph libceph: directly skip to the end of redirect reply 2020-03-30 12:42:41 +02:00
core neigh: support smaller retrans_time settting 2020-04-02 17:55:26 -07:00
dcb
dccp Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2020-02-29 15:53:35 -08:00
decnet Remove DST_HOST 2020-03-23 21:57:44 -07:00
dns_resolver KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
dsa net: dsa: dsa_bridge_mtu_normalization() can be static 2020-04-02 06:51:56 -07:00
ethernet net: remove eth_change_mtu 2020-01-27 11:09:31 +01:00
ethtool ethtool: provide timestamping information with TSINFO_GET request 2020-03-29 22:32:37 -07:00
hsr Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
ieee802154 nl802154: add missing attribute validation for dev_type 2020-03-03 13:28:48 -08:00
ife
ipv4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
ipv6 ipv6: rpl: fix loop iteration 2020-04-06 10:05:42 -07:00
iucv
kcm net: kcm: kcmproc.c: Fix RCU list suspicious usage warning 2020-03-16 17:14:02 -07:00
key
l2tp l2tp: Replace zero-length array with flexible-array member 2020-02-28 12:08:37 -08:00
l3mdev
lapb
llc af_llc: fix if-statement empty body warning 2020-02-26 20:38:13 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-30 20:48:43 -07:00
mac802154
mpls net: add net available in build_state 2020-03-29 22:30:57 -07:00
mptcp mptcp: add some missing pr_fmt defines 2020-04-03 16:06:32 -07:00
ncsi net/ncsi: Support for multi host mellanox card 2020-01-09 18:36:22 -08:00
netfilter x86: update AS_* macros to binutils >=2.23, supporting ADX and AVX2 2020-04-09 00:12:48 +09:00
netlabel netlabel_domainhash.c: Use built-in RCU list checking 2020-02-18 12:44:23 -08:00
netlink Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
netrom net: netrom: Add missing annotation for nr_neigh_stop() 2020-02-24 13:26:49 -08:00
nfc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
nsh
openvswitch net: openvswitch: use hlist_for_each_entry_rcu instead of hlist_for_each_entry 2020-04-02 17:48:12 -07:00
packet net/packet: tpacket_rcv: avoid a producer race condition 2020-03-15 00:25:25 -07:00
phonet net: Remove redundant BUG_ON() check in phonet_pernet 2020-01-03 12:25:50 -08:00
psample
qrtr net: qrtr: Fix FIXME related to qrtr_ns_init() 2020-03-03 17:52:21 -08:00
rds net/rds: Track user mapped pages through special API 2020-02-16 18:37:09 -08:00
rfkill
rose Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-01-26 10:40:21 +01:00
rxrpc KEYS: Don't write out to userspace while holding key semaphore 2020-03-29 12:40:41 +01:00
sched net_sched: fix a missing refcnt in tcindex_init() 2020-04-03 16:00:08 -07:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-30 20:48:43 -07:00
smc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
strparser
sunrpc svcrdma: Fix trace point use-after-free race 2020-04-17 12:40:38 -04:00
switchdev net: switchdev: do not propagate bridge updates across bridges 2020-02-26 20:58:33 -08:00
tipc tipc: Add a missing case of TIPC_DIRECT_MSG type 2020-03-26 11:21:02 -07:00
tls net/tls: Annotate access to sk_prot with READ_ONCE/WRITE_ONCE 2020-03-21 20:08:17 -07:00
unix net: datagram: drop 'destructor' argument from several helpers 2020-02-28 12:12:53 -08:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-02-27 18:31:39 -08:00
wimax
wireless SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
x25 net: x25: convert to list_for_each_entry_safe() 2020-02-16 18:59:42 -08:00
xdp xdp: Replace zero-length array with flexible-array member 2020-02-28 12:08:37 -08:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2020-03-30 10:59:20 -07:00
compat.c net: abstract out normal and compat msghdr import 2020-03-10 09:12:49 -06:00
Kconfig net: Fix CONFIG_NET_CLS_ACT=n and CONFIG_NFT_FWD_NETDEV={y, m} build 2020-03-25 12:24:33 -07:00
Makefile mptcp: Add MPTCP socket stubs 2020-01-24 13:44:07 +01:00
socket.c for-5.7/io_uring-2020-03-29 2020-03-30 12:18:49 -07:00
sysctl_net.c