linux/net
Daniel Borkmann 2e43f95dd8 bpf: fix shift upon scatterlist ring wrap-around in bpf_msg_pull_data
If first_sg and last_sg wraps around in the scatterlist ring, then we
need to account for that in the shift as well. E.g. crafting such msgs
where this is the case leads to a hang as shift becomes negative. E.g.
consider the following scenario:

  first_sg := 14     |=>    shift := -12     msg->sg_start := 10
  last_sg  :=  3     |                       msg->sg_end   :=  5

round  1:  i := 15, move_from :=   3, sg[15] := sg[  3]
round  2:  i :=  0, move_from := -12, sg[ 0] := sg[-12]
round  3:  i :=  1, move_from := -11, sg[ 1] := sg[-11]
round  4:  i :=  2, move_from := -10, sg[ 2] := sg[-10]
[...]
round 13:  i := 11, move_from :=  -1, sg[ 2] := sg[ -1]
round 14:  i := 12, move_from :=   0, sg[ 2] := sg[  0]
round 15:  i := 13, move_from :=   1, sg[ 2] := sg[  1]
round 16:  i := 14, move_from :=   2, sg[ 2] := sg[  2]
round 17:  i := 15, move_from :=   3, sg[ 2] := sg[  3]
[...]

This means we will loop forever and never hit the msg->sg_end condition
to break out of the loop. When we see that the ring wraps around, then
the shift should be MAX_SKB_FRAGS - first_sg + last_sg - 1. Meaning,
the remainder slots from the tail of the ring and the head until last_sg
combined.

Fixes: 015632bb30 ("bpf: sk_msg program helper bpf_sk_msg_pull_data")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-08-29 10:47:17 -07:00
..
6lowpan 6lowpan: iphc: reset mac_header after decompress to fix panic 2018-07-06 12:32:12 +02:00
9p Pull request for inclusion in 4.19, take two 2018-08-17 17:27:58 -07:00
802
8021q net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
appletalk Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
atm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
ax25 ax25: remove blank line at EOF 2018-07-24 14:10:42 -07:00
batman-adv Merge ra.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux 2018-07-20 21:17:12 -07:00
bluetooth Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
bpf bpf/test_run: support cgroup local storage 2018-08-03 00:47:32 +02:00
bpfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
bridge net/bridge/br_multicast: remove redundant variable "err" 2018-08-06 10:33:44 -07:00
caif net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
can Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
ceph crush: fix using plain integer as NULL warning 2018-08-13 17:55:44 +02:00
core bpf: fix shift upon scatterlist ring wrap-around in bpf_msg_pull_data 2018-08-29 10:47:17 -07:00
dcb net: dcb: Add priority-to-DSCP map getters 2018-07-27 13:17:50 -07:00
dccp Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-09 11:52:36 -07:00
decnet decnet: fix using plain integer as NULL warning 2018-08-09 14:11:24 -07:00
dns_resolver net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
dsa net: dsa: Drop GPIO includes 2018-08-27 15:24:33 -07:00
ethernet
hsr
ieee802154 net: ieee802154: 6lowpan: remove redundant pointers 'fq' and 'net' 2018-08-06 11:21:15 +02:00
ife
ipv4 erspan: set erspan_ver to 1 by default when adding an erspan dev 2018-08-27 15:13:17 -07:00
ipv6 erspan: set erspan_ver to 1 by default when adding an erspan dev 2018-08-27 15:13:17 -07:00
iucv net:af_iucv: get rid of the unneeded variable 'err' in afiucv_pm_freeze 2018-08-08 09:39:36 -07:00
kcm net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
key Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-07-27 09:33:37 -07:00
l2tp l2tp: fix unused function warning 2018-08-13 20:45:49 -07:00
l3mdev
lapb
llc Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-09 11:52:36 -07:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
mac802154 net: mac802154: tx: expand tailroom if necessary 2018-08-06 11:21:37 +02:00
mpls mpls: remove trailing whitepace 2018-07-24 14:10:42 -07:00
ncsi net/ncsi: Fixup .dumpit message flags and ID check in Netlink handler 2018-08-22 21:39:08 -07:00
netfilter treewide: convert ISO_8859-1 text comments to utf-8 2018-08-23 18:48:43 -07:00
netlabel
netlink Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-05 13:04:31 -07:00
netrom Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
nfc net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
nsh nsh: set mac len based on inner packet 2018-07-12 16:55:29 -07:00
openvswitch Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
packet packet: switch kvzalloc to allocate memory 2018-08-13 09:21:05 -07:00
phonet Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
psample
qrtr net: qrtr: Reset the node and port ID of broadcast messages 2018-07-05 20:20:03 +09:00
rds net/rds: Use rdma_read_gids to get connection SGID/DGID in IPv6 2018-08-27 15:26:01 -07:00
rfkill leds: triggers: let struct led_trigger::activate() return an error code 2018-07-05 23:21:10 +02:00
rose Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
rxrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
sched net: sched: return -ENOENT when trying to remove filter from non-existent chain 2018-08-27 15:16:16 -07:00
sctp sctp: remove useless start_fail from sctp_ht_iter in proc 2018-08-27 15:13:17 -07:00
smc RDMA/smc: Replace ib_query_gid with rdma_get_gid_attr 2018-08-17 16:45:51 -06:00
strparser strparser: remove redundant variable 'rd_desc' 2018-08-01 10:00:06 -07:00
sunrpc NFS client updates for Linux 4.19 2018-08-23 16:03:58 -07:00
switchdev
tipc tipc: fix the big/little endian issue in tipc_dest 2018-08-27 15:23:31 -07:00
tls tls: possible hang when do_tcp_sendpages hits sndbuf is full case 2018-08-22 21:57:14 +02:00
unix af_unix: ensure POLLOUT on remote close() for connected dgram socket 2018-08-03 16:44:19 -07:00
vmw_vsock vsock: split dwork to avoid reinitializations 2018-08-07 12:39:13 -07:00
wimax wimax: remove blank lines at EOF 2018-07-24 14:10:42 -07:00
wireless Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-07-24 19:21:58 -07:00
x25 x25: remove blank lines at EOF 2018-07-24 14:10:42 -07:00
xdp xsk: fix return value of xdp_umem_assign_dev() 2018-08-21 22:06:53 +02:00
xfrm Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
compat.c net: avoid unnecessary sock_flag() check when enable timestamp 2018-08-06 10:42:48 -07:00
Kconfig net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
Makefile bpfilter: check compiler capability in Kconfig 2018-06-28 13:36:39 +09:00
socket.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-08-15 15:04:25 -07:00
sysctl_net.c