linux_dsm_epyc7002/net
Willem de Bruijn e7c87bd6cc bpf: in __bpf_redirect_no_mac pull mac only if present
Syzkaller was able to construct a packet of negative length by
redirecting from bpf_prog_test_run_skb with BPF_PROG_TYPE_LWT_XMIT:

    BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:345 [inline]
    BUG: KASAN: slab-out-of-bounds in skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline]
    BUG: KASAN: slab-out-of-bounds in __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
    Read of size 4294967282 at addr ffff8801d798009c by task syz-executor2/12942

    kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
    check_memory_region_inline mm/kasan/kasan.c:260 [inline]
    check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
    memcpy+0x23/0x50 mm/kasan/kasan.c:302
    memcpy include/linux/string.h:345 [inline]
    skb_copy_from_linear_data include/linux/skbuff.h:3421 [inline]
    __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
    __pskb_copy include/linux/skbuff.h:1053 [inline]
    pskb_copy include/linux/skbuff.h:2904 [inline]
    skb_realloc_headroom+0xe7/0x120 net/core/skbuff.c:1539
    ipip6_tunnel_xmit net/ipv6/sit.c:965 [inline]
    sit_tunnel_xmit+0xe1b/0x30d0 net/ipv6/sit.c:1029
    __netdev_start_xmit include/linux/netdevice.h:4325 [inline]
    netdev_start_xmit include/linux/netdevice.h:4334 [inline]
    xmit_one net/core/dev.c:3219 [inline]
    dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3235
    __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3805
    dev_queue_xmit+0x17/0x20 net/core/dev.c:3838
    __bpf_tx_skb net/core/filter.c:2016 [inline]
    __bpf_redirect_common net/core/filter.c:2054 [inline]
    __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2061
    ____bpf_clone_redirect net/core/filter.c:2094 [inline]
    bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2066
    bpf_prog_41f2bcae09cd4ac3+0xb25/0x1000

The generated test constructs a packet with mac header, network
header, skb->data pointing to network header and skb->len 0.

Redirecting to a sit0 through __bpf_redirect_no_mac pulls the
mac length, even though skb->data already is at skb->network_header.
bpf_prog_test_run_skb has already pulled it as LWT_XMIT !is_l2.

Update the offset calculation to pull only if skb->data differs
from skb->network_header, which is not true in this case.

The test itself can be run only from commit 1cf1cae963 ("bpf:
introduce BPF_PROG_TEST_RUN command"), but the same type of packets
with skb at network header could already be built from lwt xmit hooks,
so this fix is more relevant to that commit.

Also set the mac header on redirect from LWT_XMIT, as even after this
change to __bpf_redirect_no_mac that field is expected to be set, but
is not yet in ip_finish_output2.

Fixes: 3a0af8fd61 ("bpf: BPF for lightweight tunnel infrastructure")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-20 01:11:48 +01:00
..
6lowpan 6lowpan: convert to DEFINE_SHOW_ATTRIBUTE 2018-12-19 00:28:05 +01:00
9p 9p/net: put a lower bound on msize 2018-12-25 17:07:49 +09:00
802
8021q net: core: dev: Add extack argument to dev_change_flags() 2018-12-06 13:26:07 -08:00
appletalk Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
atm Revert "net: simplify sock_poll_wait" 2018-10-23 10:57:06 -07:00
ax25 ax25: fix a use-after-free in ax25_fillin_cb() 2018-12-30 14:07:54 -08:00
batman-adv Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
bluetooth Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-12-27 13:53:32 -08:00
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-12-10 18:00:43 -08:00
bpfilter net: bpfilter: disallow to remove bpfilter module while being used 2019-01-11 18:05:41 -08:00
bridge net: clear skb->tstamp in bridge forwarding path 2019-01-11 18:26:01 -08:00
caif Revert "net: simplify sock_poll_wait" 2018-10-23 10:57:06 -07:00
can can: gw: ensure DLC boundaries after CAN frame modification 2019-01-07 05:17:51 -08:00
ceph libceph: allow setting abort_on_full for rbd 2019-01-07 22:47:48 +01:00
core bpf: in __bpf_redirect_no_mac pull mac only if present 2019-01-20 01:11:48 +01:00
dcb net: dcb: Add priority-to-DSCP map getters 2018-07-27 13:17:50 -07:00
dccp mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
decnet mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
dns_resolver dns: Allow the dns resolver to retrieve a server set 2018-10-04 09:40:52 -07:00
dsa net: dsa: ksz: Add STP multicast handling 2018-12-16 14:23:33 -08:00
ethernet net: ethernet: provide nvmem_get_mac_address() 2018-12-03 15:40:30 -08:00
hsr
ieee802154 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-24 16:19:56 -08:00
ife
ipv4 net: bpfilter: disallow to remove bpfilter module while being used 2019-01-11 18:05:41 -08:00
ipv6 ipv6: fix kernel-infoleak in ipv6_local_error() 2019-01-10 09:36:41 -05:00
iucv iucv: Remove SKB list assumptions. 2018-11-10 16:55:11 -08:00
kcm Revert "kcm: remove any offset before parsing messages" 2018-09-17 18:43:42 -07:00
key af_key: fix indentation on declaration statement 2018-11-15 18:09:32 +01:00
l2tp ppp: Move PFC decompression to PPP generic layer 2018-12-20 16:49:30 -08:00
l3mdev l3mdev: add function to retreive upper master 2018-12-03 14:15:26 -08:00
lapb
llc llc: do not use sk_eat_skb() 2018-10-22 19:59:20 -07:00
mac80211 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-12-27 13:53:32 -08:00
mac802154 mac802154: Remove VLA usage of skcipher 2018-09-28 12:46:07 +08:00
mpls net/mpls: Handle kernel side filtering of route dumps 2018-10-16 00:14:07 -07:00
ncsi net/ncsi: Add NCSI Mellanox OEM command 2018-11-27 16:37:20 -08:00
netfilter jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
netlabel netlabel: check for IPV4MASK in addrinfo_get 2018-09-21 18:58:34 -07:00
netlink net: netlink: rename NETLINK_DUMP_STRICT_CHK -> NETLINK_GET_STRICT_CHK 2018-12-14 11:44:31 -08:00
netrom netrom: fix locking in nr_find_socket() 2018-12-30 20:24:16 -08:00
nfc net: Revert recent Spectre-v1 patches. 2018-12-23 16:01:35 -08:00
nsh nsh: set mac len based on inner packet 2018-07-12 16:55:29 -07:00
openvswitch openvswitch: Fix IPv6 later frags parsing 2019-01-04 13:00:02 -08:00
packet packet: Do not leak dev refcounts on error exit 2019-01-08 21:41:40 -05:00
phonet net: Revert recent Spectre-v1 patches. 2018-12-23 16:01:35 -08:00
psample
qrtr net: qrtr: Reset the node and port ID of broadcast messages 2018-07-05 20:20:03 +09:00
rds rds: use DIV_ROUND_UP instead of ceil 2019-01-07 07:22:36 -08:00
rfkill rfkill: gpio: Remove unused include 2018-12-18 13:13:56 +01:00
rose Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL 2018-06-28 10:40:47 -07:00
rxrpc rxrpc: Fix life check 2018-11-15 11:35:40 -08:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-12-27 13:04:52 -08:00
sctp mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
smc smc: move unhash as early as possible in smc_release() 2019-01-07 14:40:27 -05:00
strparser bpf, sockmap: convert to generic sk_msg interface 2018-10-15 12:23:19 -07:00
sunrpc Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
switchdev net: switchdev: Add extack to switchdev_handle_port_obj_add() callback 2018-12-12 16:34:22 -08:00
tipc tipc: fix memory leak in tipc_nl_compat_publ_dump 2019-01-07 11:42:08 -05:00
tls Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-21 15:06:20 -08:00
unix Revert "net: simplify sock_poll_wait" 2018-10-23 10:57:06 -07:00
vmw_vsock VSOCK: Send reset control packet when socket is partially bound 2018-12-18 11:53:42 -08:00
wimax wimax: remove blank lines at EOF 2018-07-24 14:10:42 -07:00
wireless Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-12-27 13:53:32 -08:00
x25 net/x25: handle call collisions 2018-11-29 14:25:36 -08:00
xdp xsk: Check if a queue exists during umem setup 2019-01-15 20:51:57 +01:00
xfrm Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-12-20 11:53:36 -08:00
compat.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
Kconfig net: convert bridge_nf to use skb extension infrastructure 2018-12-19 11:21:37 -08:00
Makefile bpfilter: check compiler capability in Kconfig 2018-06-28 13:36:39 +09:00
socket.c y2038: more syscalls and cleanups 2018-12-28 12:45:04 -08:00
sysctl_net.c