linux/net/tipc
Xin Long ff48b6222e tipc: use skb_unshare() instead in tipc_buf_append()
In tipc_buf_append() it may change skb's frag_list, and it causes
problems when this skb is cloned. skb_unclone() doesn't really
make this skb's flag_list available to change.

Shuang Li has reported an use-after-free issue because of this
when creating quite a few macvlan dev over the same dev, where
the broadcast packets will be cloned and go up to the stack:

 [ ] BUG: KASAN: use-after-free in pskb_expand_head+0x86d/0xea0
 [ ] Call Trace:
 [ ]  dump_stack+0x7c/0xb0
 [ ]  print_address_description.constprop.7+0x1a/0x220
 [ ]  kasan_report.cold.10+0x37/0x7c
 [ ]  check_memory_region+0x183/0x1e0
 [ ]  pskb_expand_head+0x86d/0xea0
 [ ]  process_backlog+0x1df/0x660
 [ ]  net_rx_action+0x3b4/0xc90
 [ ]
 [ ] Allocated by task 1786:
 [ ]  kmem_cache_alloc+0xbf/0x220
 [ ]  skb_clone+0x10a/0x300
 [ ]  macvlan_broadcast+0x2f6/0x590 [macvlan]
 [ ]  macvlan_process_broadcast+0x37c/0x516 [macvlan]
 [ ]  process_one_work+0x66a/0x1060
 [ ]  worker_thread+0x87/0xb10
 [ ]
 [ ] Freed by task 3253:
 [ ]  kmem_cache_free+0x82/0x2a0
 [ ]  skb_release_data+0x2c3/0x6e0
 [ ]  kfree_skb+0x78/0x1d0
 [ ]  tipc_recvmsg+0x3be/0xa40 [tipc]

So fix it by using skb_unshare() instead, which would create a new
skb for the cloned frag and it'll be safe to change its frag_list.
The similar things were also done in sctp_make_reassembled_event(),
which is using skb_copy().

Reported-by: Shuang Li <shuali@redhat.com>
Fixes: 37e22164a8 ("tipc: rename and move message reassembly function")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 16:39:58 -07:00
..
addr.c tipc: initialise addr_trail_end when setting node addresses 2019-08-11 21:40:04 -07:00
addr.h
bcast.c tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
bcast.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
bearer.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
bearer.h tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
core.c tipc: fix ordering of tipc module init and exit routine 2019-12-06 12:01:09 -08:00
core.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-11-16 21:51:42 -08:00
crypto.c tipc: fix using smp_processor_id() in preemptible 2020-08-30 19:12:17 -07:00
crypto.h tipc: introduce TIPC encryption & authentication 2019-11-08 14:01:59 -08:00
diag.c tipc: switch to rhashtable iterator 2018-08-29 18:04:54 -07:00
discover.c net: tipc: kerneldoc fixes 2020-07-13 17:20:40 -07:00
discover.h
eth_media.c tipc: Use is_broadcast_ether_addr() instead of memcmp() 2020-08-03 16:21:46 -07:00
group.c tipc: Fix memory leak in tipc_group_create_member() 2020-09-14 16:36:20 -07:00
group.h tipc: extend sock diag for group communication 2018-06-30 21:05:42 +09:00
ib_media.c tipc: introduce variable window congestion control 2019-12-10 17:31:15 -08:00
Kconfig tipc: not enable tipc when ipv6 works as a module 2020-08-16 21:04:55 -07:00
link.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
link.h tipc: add support for broadcast rcv stats dumping 2020-05-26 15:16:52 -07:00
Makefile tipc: remove meaningless assignment in Makefile 2020-01-08 12:38:54 -08:00
monitor.c tipc: add NULL pointer check to prevent kernel oops 2020-03-15 00:07:00 -07:00
monitor.h tipc: update mon's self addr when node addr generated 2019-11-12 19:45:45 -08:00
msg.c tipc: use skb_unshare() instead in tipc_buf_append() 2020-09-14 16:39:58 -07:00
msg.h tipc: Use struct_size() helper 2020-06-19 20:15:25 -07:00
name_distr.c tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
name_distr.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
name_table.c tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
name_table.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
net.c tipc: make legacy address flag readable over netlink 2019-12-20 21:18:42 -08:00
net.h tipc: make legacy address flag readable over netlink 2019-12-20 21:18:42 -08:00
netlink_compat.c tipc: fix uninit skb->data in tipc_nl_compat_dumpit() 2020-08-16 21:03:19 -07:00
netlink.c tipc: add support for broadcast rcv stats dumping 2020-05-26 15:16:52 -07:00
netlink.h net: tipc: allocate attrs locally instead of using genl_family_attrbuf in compat_dumpit() 2019-10-06 15:44:47 +02:00
node.c net: tipc: kerneldoc fixes 2020-07-13 17:20:40 -07:00
node.h tipc: update a binding service via broadcast 2020-06-17 08:53:34 -07:00
socket.c tipc: fix shutdown() of connection oriented socket 2020-09-10 12:21:39 -07:00
socket.h tipc: call tsk_set_importance from tipc_topsrv_create_listener 2020-05-28 11:11:46 -07:00
subscr.c
subscr.h tipc: fix failed service subscription deletion 2020-05-13 12:33:19 -07:00
sysctl.c tipc: enable broadcast retrans via unicast 2020-05-26 15:16:52 -07:00
topsrv.c tipc: call tsk_set_importance from tipc_topsrv_create_listener 2020-05-28 11:11:46 -07:00
topsrv.h
trace.c tipc: remove unneeded semicolon in trace.c 2019-01-17 22:04:43 -08:00
trace.h tipc: add support for broadcast rcv stats dumping 2020-05-26 15:16:52 -07:00
udp_media.c ipv6: some fixes for ipv6_dev_find() 2020-08-18 15:58:53 -07:00
udp_media.h tipc: implement configuration of UDP media MTU 2018-04-20 11:04:05 -04:00