linux/net
David Howells d7e15835ab rxrpc: Kernel calls get stuck in recvmsg
Calls made through the in-kernel interface can end up getting stuck because
of a missed variable update in a loop in rxrpc_recvmsg_data().  The problem
is like this:

 (1) A new packet comes in and doesn't cause a notification to be given to
     the client as there's still another packet in the ring - the
     assumption being that if the client will keep drawing off data until
     the ring is empty.

 (2) The client is in rxrpc_recvmsg_data(), inside the big while loop that
     iterates through the packets.  This copies the window pointers into
     variables rather than using the information in the call struct
     because:

     (a) MSG_PEEK might be in effect;

     (b) we need a barrier after reading call->rx_top to pair with the
     	 barrier in the softirq routine that loads the buffer.

 (3) The reading of call->rx_top is done outside of the loop, and top is
     never updated whilst we're in the loop.  This means that even through
     there's a new packet available, we don't see it and may return -EFAULT
     to the caller - who will happily return to the scheduler and await the
     next notification.

 (4) No further notifications are forthcoming until there's an abort as the
     ring isn't empty.

The fix is to move the read of call->rx_top inside the loop - but it needs
to be done before the condition is checked.

Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-26 21:30:12 -05:00
..
6lowpan 6lowpan: use rb_entry() 2017-01-22 16:46:13 -05:00
9p
802 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
8021q net: remove ndo_neigh_{construct, destroy} from stacked devices 2017-02-06 11:25:57 -05:00
appletalk
atm net: atm: Fix warnings in net/atm/lec.c when !CONFIG_PROC_FS 2016-12-28 15:11:32 -05:00
ax25 ax25: Fix segfault after sock connection timeout 2017-01-16 14:39:58 -05:00
batman-adv Here are two fixes for batman-adv for net-next: 2017-01-29 19:21:26 -05:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
bridge bridge: don't indicate expiry on NTF_EXT_LEARNED fdb entries 2017-02-17 13:56:56 -05:00
caif net: caif: Remove unused stats member from struct chnl_net 2017-01-19 11:45:21 -05:00
can can: bcm: fix hrtimer/tasklet termination in bcm op removal 2017-01-30 11:05:04 +01:00
ceph Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-02-20 13:23:30 -08:00
core bpf: Fix bpf_xdp_event_output 2017-02-23 13:53:42 -05:00
dcb net: dcb: set error code on failures 2016-12-03 23:54:25 -05:00
dccp net/dccp: fix use after free in tw_timer_handler() 2017-02-22 16:14:07 -05:00
decnet Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
dns_resolver
dsa Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-11 02:31:11 -05:00
ethernet Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2017-02-16 21:25:49 -05:00
hsr net/hsr: use eth_hw_addr_random() 2017-02-21 13:25:22 -05:00
ieee802154 Makefile: drop -D__CHECK_ENDIAN__ from cflags 2016-12-16 00:13:43 +02:00
ife net: Introduce ife encapsulation module 2017-02-03 15:16:45 -05:00
ipv4 ipv4: mask tos for input route 2017-02-26 11:03:38 -05:00
ipv6 ipv6: check sk sk_type and protocol early in ip_mroute_set/getsockopt 2017-02-26 21:25:46 -05:00
ipx ktime: Get rid of the union 2016-12-25 17:21:22 +01:00
irda irda: Fix lockdep annotations in hashbin_delete(). 2017-02-17 16:19:39 -05:00
iucv net/af_iucv: don't use paged skbs for TX on HiperSockets 2017-01-10 21:08:29 -05:00
kcm kcm: fix a null pointer dereference in kcm_sendmsg() 2017-02-14 13:06:37 -05:00
key netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
l2tp l2tp: Avoid schedule while atomic in exit_net 2017-02-22 15:59:53 -05:00
l3mdev
lapb Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
llc net/llc: avoid BUG_ON() in skb_orphan() 2017-02-12 22:14:49 -05:00
mac80211 Some more updates: 2017-02-10 14:31:51 -05:00
mac802154 ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
mpls net: mpls: Add support for netconf 2017-02-20 11:13:37 -05:00
ncsi
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2017-02-23 10:59:15 -05:00
netlabel netlabel: add CALIPSO to the list of built-in protocols 2017-01-06 22:20:45 -05:00
netlink net: adjust skb->truesize in pskb_expand_head() 2017-01-27 12:03:29 -05:00
netrom
nfc
openvswitch openvswitch: Set event bit after initializing labels. 2017-02-20 10:18:43 -05:00
packet Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-19 11:18:46 -05:00
phonet netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
psample net: Introduce psample, a new genetlink channel for packet sampling 2017-01-24 13:44:28 -05:00
qrtr net: qrtr: Mark 'buf' as little endian 2017-01-10 20:45:04 -05:00
rds rds: fix memory leak error 2017-02-24 14:13:14 -05:00
rfkill rfkill: remove rfkill-regulator 2017-01-24 11:07:35 +01:00
rose Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
rxrpc rxrpc: Kernel calls get stuck in recvmsg 2017-02-26 21:30:12 -05:00
sched net sched actions: decrement module reference count after table flush. 2017-02-26 21:28:41 -05:00
sctp sctp: set sin_port for addr param when checking duplicate address 2017-02-26 21:24:05 -05:00
smc smc: some potential use after free bugs 2017-01-30 16:37:55 -05:00
strparser
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
switchdev
tipc tipc: move premature initilalization of stack variables 2017-02-24 11:42:54 -05:00
unix unix: add ioctl to open a unix socket file with O_PATH 2017-02-02 21:58:02 -05:00
vmw_vsock Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-12-17 20:17:04 -08:00
wimax
wireless Some more updates: 2017-02-10 14:31:51 -05:00
x25 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2017-02-16 21:25:49 -05:00
compat.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2017-02-22 10:15:09 -08:00
Kconfig bpf: make jited programs visible in traces 2017-02-17 13:40:05 -05:00
Makefile net: Introduce ife encapsulation module 2017-02-03 15:16:45 -05:00
socket.c net: socket: fix recvmmsg not returning error from sock_error 2017-02-21 13:35:25 -05:00
sysctl_net.c