android_kernel_oneplus_msm8998/net
Eric Dumazet 94801fd5ab ax25: fix possible use-after-free
commit 63530aba7826a0f8e129874df9c4d264f9db3f9e upstream.

syzbot found that ax25 routes where not properly protected
against concurrent use [1].

In this particular report the bug happened while
copying ax25->digipeat.

Fix this problem by making sure we call ax25_get_route()
while ax25_route_lock is held, so that no modification
could happen while using the route.

The current two ax25_get_route() callers do not sleep,
so this change should be fine.

Once we do that, ax25_get_route() no longer needs to
grab a reference on the found route.

[1]
ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline]
BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113
Read of size 66 at addr ffff888066641a80 by task syz-executor2/531

ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x123/0x190 mm/kasan/generic.c:191
 memcpy+0x24/0x50 mm/kasan/common.c:130
 memcpy include/linux/string.h:352 [inline]
 kmemdup+0x42/0x60 mm/util.c:113
 kmemdup include/linux/string.h:425 [inline]
 ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424
 ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224
 __sys_connect+0x357/0x490 net/socket.c:1664
 __do_sys_connect net/socket.c:1675 [inline]
 __se_sys_connect net/socket.c:1672 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1672
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f870ee22c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f870ee236d4
R13: 00000000004be48e R14: 00000000004ce9a8 R15: 00000000ffffffff

Allocated by task 526:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 ax25_rt_add net/ax25/ax25_route.c:95 [inline]
 ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233
 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
 sock_do_ioctl+0xe2/0x400 net/socket.c:950
 sock_ioctl+0x32f/0x6c0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
Freed by task 550:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 ax25_rt_add net/ax25/ax25_route.c:92 [inline]
 ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233
 ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
 sock_do_ioctl+0xe2/0x400 net/socket.c:950
 sock_ioctl+0x32f/0x6c0 net/socket.c:1074
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888066641a80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 0 bytes inside of
 96-byte region [ffff888066641a80, ffff888066641ae0)
The buggy address belongs to the page:
page:ffffea0001999040 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0x0
flags: 0x1fffc0000000200(slab)
ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
raw: 01fffc0000000200 ffffea0001817948 ffffea0002341dc8 ffff88812c3f04c0
raw: 0000000000000000 ffff888066641000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888066641980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888066641a00: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc
>ffff888066641a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                   ^
 ffff888066641b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888066641b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-23 09:05:14 +01:00
..
6lowpan 6lowpan: iphc: reset mac_header after decompress to fix panic 2018-10-10 08:52:04 +02:00
9p 9p/net: put a lower bound on msize 2019-01-13 10:05:33 +01:00
802
8021q vlan: also check phy_driver ts_info for vlan's real device 2018-04-13 19:50:25 +02:00
appletalk
atm net: atm: Fix potential Spectre v1 2018-05-16 10:06:51 +02:00
ax25 ax25: fix possible use-after-free 2019-02-23 09:05:14 +01:00
batman-adv batman-adv: Force mac header to start of data on xmit 2019-02-20 10:13:20 +01:00
bluetooth Bluetooth: Fix unnecessary error message for HCI request completion 2019-02-20 10:13:10 +01:00
bridge net: bridge: Fix ethernet header pointer before check skb forwardable 2019-02-06 19:43:03 +01:00
caif net: caif: Add a missing rcu_read_unlock() in caif_flow_cb 2018-09-05 09:18:34 +02:00
can can: bcm: check timer values before ktime conversion 2019-02-06 19:43:04 +01:00
ceph libceph: avoid KEEPALIVE_PENDING races in ceph_con_keepalive() 2019-02-20 10:13:20 +01:00
core net: Do not allocate page fragments that are not skb aligned 2019-02-23 09:05:14 +01:00
dcb net: dcb: For wild-card lookups, use priority -1, not 0 2018-09-19 22:48:58 +02:00
dccp dccp: fool proof ccid_hc_[rt]x_parse_options() 2019-02-20 10:13:15 +01:00
decnet dn_getsockoptdecnet: move nf_{get/set}sockopt outside sock lock 2018-02-25 11:03:38 +01:00
dns_resolver KEYS: DNS: fix parsing multiple options 2018-07-22 14:25:54 +02:00
dsa net: dsa: slave: Don't propagate flag changes on down slave interfaces 2019-02-20 10:13:15 +01:00
ethernet net: introduce device min_header_len 2017-02-18 16:39:27 +01:00
hsr net/hsr: fix a warning message 2015-11-23 14:56:15 -05:00
ieee802154 inet: frags: fix ip6frag_low_thresh boundary 2019-02-08 11:25:32 +01:00
ipv4 net: ipv4: use a dedicated counter for icmp_v4 redirect packets 2019-02-23 09:05:14 +01:00
ipv6 net: fix IPv6 prefix route residue 2019-02-23 09:05:13 +01:00
ipx ipx: call ipxitf_put() in ioctl error path 2017-05-25 14:30:13 +02:00
irda irda: Only insert new objects into the global database via setsockopt 2018-09-15 09:40:40 +02:00
iucv af_iucv: Move sockaddr length checks to before accessing sa_family in bind and connect handlers 2018-11-10 07:41:35 -08:00
key af_key: Always verify length of provided sadb_key 2018-06-16 09:54:25 +02:00
l2tp l2tp: fix reading optional fields of L2TPv3 2019-02-06 19:43:06 +01:00
l3mdev net: Add netif_is_l3_slave 2015-10-07 04:27:43 -07:00
lapb
llc llc: do not use sk_eat_skb() 2018-12-01 09:46:34 +01:00
mac80211 mac80211: ensure that mgmt tx skbs have tailroom for encryption 2019-02-20 10:13:19 +01:00
mac802154 net: mac802154: tx: expand tailroom if necessary 2018-09-09 20:04:32 +02:00
mpls mpls, nospec: Sanitize array index in mpls_label_ok() 2018-03-11 16:19:47 +01:00
netfilter netfilter: nf_tables: fix oops when inserting an element into a verdict map 2018-12-01 09:46:40 +01:00
netlabel netlabel: check for IPV4MASK in addrinfo_get 2018-10-20 09:52:36 +02:00
netlink netlink: Don't shift on 64 for ngroups 2018-08-09 12:19:28 +02:00
netrom netrom: switch to sock timer API 2019-02-06 19:43:06 +01:00
nfc NFC: Fix possible memory corruption when handling SHDLC I-Frame commands 2018-09-29 03:08:51 -07:00
openvswitch openvswitch: Avoid OOB read when parsing flow nlattrs 2019-02-06 19:43:03 +01:00
packet packet: Do not leak dev refcounts on error exit 2019-01-26 09:42:49 +01:00
phonet phonet: properly unshare skbs in phonet_rcv() 2016-01-31 11:29:00 -08:00
rds rds: avoid unenecessary cong_update in loop transport 2018-07-22 14:25:54 +02:00
rfkill rfkill: gpio: fix memory leak in probe error path 2018-05-16 10:06:51 +02:00
rose net/rose: fix NULL ax25_cb kernel panic 2019-02-06 19:43:06 +01:00
rxrpc rxrpc: check return value of skb_to_sgvec always 2018-04-13 19:50:23 +02:00
sched net_sched: refetch skb protocol for each filter 2019-02-06 19:43:03 +01:00
sctp sctp: allocate sctp_sockaddr_entry with kzalloc 2019-01-26 09:42:51 +01:00
sunrpc sunrpc: handle ENOMEM in rpcb_getport_async 2019-01-26 09:42:51 +01:00
switchdev switchdev: pass pointer to fib_info instead of copy 2016-06-24 10:18:16 -07:00
tipc tipc: use destination length for copy string 2019-02-20 10:13:14 +01:00
unix net: drop write-only stack variable 2018-11-10 07:41:34 -08:00
vmw_vsock vsock: cope with memory allocation failure at socket creation time 2019-02-23 09:05:13 +01:00
wimax net:wimax: Fix doucble word "the the" in networking.xml 2015-08-09 22:43:52 -07:00
wireless cfg80211: reg: Init wiphy_idx in regulatory_hint_core() 2018-11-10 07:41:33 -08:00
x25 net/x25: do not hold the cpu too long in x25_new_lci() 2019-02-23 09:05:14 +01:00
xfrm xfrm: refine validation of template and selector families 2019-02-20 10:13:20 +01:00
compat.c sock: Make sock->sk_stamp thread-safe 2019-01-13 10:05:28 +01:00
Kconfig Make DST_CACHE a silent config option 2018-02-25 11:03:37 +01:00
Makefile net: Introduce L3 Master device abstraction 2015-09-29 20:40:32 -07:00
socket.c net: socket: fix a missing-check bug 2018-11-10 07:41:41 -08:00
sysctl_net.c net: Use ns_capable_noaudit() when determining net sysctl permissions 2016-09-15 08:27:50 +02:00