linux/net
Alexander Potapenko 540e2894f7 net: don't call strlen() on the user buffer in packet_bind_spkt()
KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of
uninitialized memory in packet_bind_spkt():
Acked-by: Eric Dumazet <edumazet@google.com>

==================================================================
BUG: KMSAN: use of unitialized memory
CPU: 0 PID: 1074 Comm: packet Not tainted 4.8.0-rc6+ #1891
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
 0000000000000000 ffff88006b6dfc08 ffffffff82559ae8 ffff88006b6dfb48
 ffffffff818a7c91 ffffffff85b9c870 0000000000000092 ffffffff85b9c550
 0000000000000000 0000000000000092 00000000ec400911 0000000000000002
Call Trace:
 [<     inline     >] __dump_stack lib/dump_stack.c:15
 [<ffffffff82559ae8>] dump_stack+0x238/0x290 lib/dump_stack.c:51
 [<ffffffff818a6626>] kmsan_report+0x276/0x2e0 mm/kmsan/kmsan.c:1003
 [<ffffffff818a783b>] __msan_warning+0x5b/0xb0
mm/kmsan/kmsan_instr.c:424
 [<     inline     >] strlen lib/string.c:484
 [<ffffffff8259b58d>] strlcpy+0x9d/0x200 lib/string.c:144
 [<ffffffff84b2eca4>] packet_bind_spkt+0x144/0x230
net/packet/af_packet.c:3132
 [<ffffffff84242e4d>] SYSC_bind+0x40d/0x5f0 net/socket.c:1370
 [<ffffffff84242a22>] SyS_bind+0x82/0xa0 net/socket.c:1356
 [<ffffffff8515991b>] entry_SYSCALL_64_fastpath+0x13/0x8f
arch/x86/entry/entry_64.o:?
chained origin: 00000000eba00911
 [<ffffffff810bb787>] save_stack_trace+0x27/0x50
arch/x86/kernel/stacktrace.c:67
 [<     inline     >] kmsan_save_stack_with_flags mm/kmsan/kmsan.c:322
 [<     inline     >] kmsan_save_stack mm/kmsan/kmsan.c:334
 [<ffffffff818a59f8>] kmsan_internal_chain_origin+0x118/0x1e0
mm/kmsan/kmsan.c:527
 [<ffffffff818a7773>] __msan_set_alloca_origin4+0xc3/0x130
mm/kmsan/kmsan_instr.c:380
 [<ffffffff84242b69>] SYSC_bind+0x129/0x5f0 net/socket.c:1356
 [<ffffffff84242a22>] SyS_bind+0x82/0xa0 net/socket.c:1356
 [<ffffffff8515991b>] entry_SYSCALL_64_fastpath+0x13/0x8f
arch/x86/entry/entry_64.o:?
origin description: ----address@SYSC_bind (origin=00000000eb400911)
==================================================================
(the line numbers are relative to 4.8-rc6, but the bug persists
upstream)

, when I run the following program as root:

=====================================
 #include <string.h>
 #include <sys/socket.h>
 #include <netpacket/packet.h>
 #include <net/ethernet.h>

 int main() {
   struct sockaddr addr;
   memset(&addr, 0xff, sizeof(addr));
   addr.sa_family = AF_PACKET;
   int fd = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ALL));
   bind(fd, &addr, sizeof(addr));
   return 0;
 }
=====================================

This happens because addr.sa_data copied from the userspace is not
zero-terminated, and copying it with strlcpy() in packet_bind_spkt()
results in calling strlen() on the kernel copy of that non-terminated
buffer.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-01 20:55:57 -08:00
..
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 lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
atm lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
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 scripts/spelling.txt: add "an user" pattern and fix typo instances 2017-02-27 18:43:46 -08:00
bridge net: bridge: allow IPv6 when multicast flood is disabled 2017-03-01 20:55:57 -08:00
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 This time around we have: 2017-02-28 15:36:09 -08:00
core net: solve a NAPI race 2017-03-01 09:50:58 -08:00
dcb net: dcb: set error code on failures 2016-12-03 23:54:25 -05:00
dccp tcp/dccp: block BH for SYN processing 2017-03-01 15:03:31 -08:00
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 lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
ife net: Introduce ife encapsulation module 2017-02-03 15:16:45 -05:00
ipv4 tcp/dccp: block BH for SYN processing 2017-03-01 15:03:31 -08:00
ipv6 net: route: add missing nla_policy entry for RTA_MARK attribute 2017-03-01 10:25:56 -08:00
ipx ktime: Get rid of the union 2016-12-25 17:21:22 +01:00
irda lib/vsprintf.c: remove %Z support 2017-02-27 18:43:47 -08:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-02-28 10:00:39 -08:00
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 First round of fixes - details in the commits: 2017-03-01 15:08:34 -08:00
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/davem/net 2017-02-28 10:00:39 -08:00
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 net: don't call strlen() on the user buffer in packet_bind_spkt() 2017-03-01 20:55:57 -08:00
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: ib: add the static type to the variables 2017-03-01 09:50:58 -08:00
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: Fix deadlock between call creation and sendmsg/recvmsg 2017-03-01 09:50:58 -08:00
sched net sched actions: do not overwrite status of action creation. 2017-02-26 21:31:32 -05:00
sctp sctp: call rcu_read_lock before checking for duplicate transport nodes 2017-03-01 09:50:58 -08:00
smc smc: some potential use after free bugs 2017-01-30 16:37:55 -05:00
strparser
sunrpc The nfsd update this round is mainly a lot of miscellaneous cleanups and 2017-02-28 15:39:09 -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 xfrm: provide correct dst in xfrm_neigh_lookup 2017-02-26 21:35:24 -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