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Apply fix for CVE-2017-7184 #50

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@euank euank commented Mar 30, 2017

.. to 4.9.16 for stable.

Andy Whitcroft added 2 commits March 30, 2017 09:05
When a new xfrm state is created during an XFRM_MSG_NEWSA call we
validate the user supplied replay_esn to ensure that the size is valid
and to ensure that the replay_window size is within the allocated
buffer.  However later it is possible to update this replay_esn via a
XFRM_MSG_NEWAE call.  There we again validate the size of the supplied
buffer matches the existing state and if so inject the contents.  We do
not at this point check that the replay_window is within the allocated
memory.  This leads to out-of-bounds reads and writes triggered by
netlink packets.  This leads to memory corruption and the potential for
priviledge escalation.

We already attempt to validate the incoming replay information in
xfrm_new_ae() via xfrm_replay_verify_len().  This confirms that the user
is not trying to change the size of the replay state buffer which
includes the replay_esn.  It however does not check the replay_window
remains within that buffer.  Add validation of the contained
replay_window.

CVE-2017-7184
Signed-off-by: Andy Whitcroft <[email protected]>
Acked-by: Steffen Klassert <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Kees Cook has pointed out that xfrm_replay_state_esn_len() is subject to
wrapping issues.  To ensure we are correctly ensuring that the two ESN
structures are the same size compare both the overall size as reported
by xfrm_replay_state_esn_len() and the internal length are the same.

CVE-2017-7184
Signed-off-by: Andy Whitcroft <[email protected]>
Acked-by: Steffen Klassert <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
@euank euank merged commit 38be103 into coreos:v4.9.16-coreos Mar 30, 2017
@euank euank deleted the CVE-2017-7184 branch March 30, 2017 17:36
coreosbot pushed a commit that referenced this pull request Jul 26, 2019
[ Upstream commit 3f167e1 ]

ipv4_pdp_add() is called in RCU read-side critical section.
So GFP_KERNEL should not be used in the function.
This patch make ipv4_pdp_add() to use GFP_ATOMIC instead of GFP_KERNEL.

Test commands:
gtp-link add gtp1 &
gtp-tunnel add gtp1 v1 100 200 1.1.1.1 2.2.2.2

Splat looks like:
[  130.618881] =============================
[  130.626382] WARNING: suspicious RCU usage
[  130.626994] 5.2.0-rc6+ #50 Not tainted
[  130.627622] -----------------------------
[  130.628223] ./include/linux/rcupdate.h:266 Illegal context switch in RCU read-side critical section!
[  130.629684]
[  130.629684] other info that might help us debug this:
[  130.629684]
[  130.631022]
[  130.631022] rcu_scheduler_active = 2, debug_locks = 1
[  130.632136] 4 locks held by gtp-tunnel/1025:
[  130.632925]  #0: 000000002b93c8b7 (cb_lock){++++}, at: genl_rcv+0x15/0x40
[  130.634159]  #1: 00000000f17bc999 (genl_mutex){+.+.}, at: genl_rcv_msg+0xfb/0x130
[  130.635487]  #2: 00000000c644ed8e (rtnl_mutex){+.+.}, at: gtp_genl_new_pdp+0x18c/0x1150 [gtp]
[  130.636936]  #3: 0000000007a1cde7 (rcu_read_lock){....}, at: gtp_genl_new_pdp+0x187/0x1150 [gtp]
[  130.638348]
[  130.638348] stack backtrace:
[  130.639062] CPU: 1 PID: 1025 Comm: gtp-tunnel Not tainted 5.2.0-rc6+ #50
[  130.641318] Call Trace:
[  130.641707]  dump_stack+0x7c/0xbb
[  130.642252]  ___might_sleep+0x2c0/0x3b0
[  130.642862]  kmem_cache_alloc_trace+0x1cd/0x2b0
[  130.643591]  gtp_genl_new_pdp+0x6c5/0x1150 [gtp]
[  130.644371]  genl_family_rcv_msg+0x63a/0x1030
[  130.645074]  ? mutex_lock_io_nested+0x1090/0x1090
[  130.645845]  ? genl_unregister_family+0x630/0x630
[  130.646592]  ? debug_show_all_locks+0x2d0/0x2d0
[  130.647293]  ? check_flags.part.40+0x440/0x440
[  130.648099]  genl_rcv_msg+0xa3/0x130
[ ... ]

Fixes: 459aa66 ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
coreosbot pushed a commit that referenced this pull request Jul 26, 2019
[ Upstream commit 1788b85 ]

gtp_encap_destroy() is called twice.
1. When interface is deleted.
2. When udp socket is destroyed.
either gtp->sk0 or gtp->sk1u could be freed by sock_put() in
gtp_encap_destroy(). so, when gtp_encap_destroy() is called again,
it would uses freed sk pointer.

patch makes gtp_encap_destroy() to set either gtp->sk0 or gtp->sk1u to
null. in addition, both gtp->sk0 and gtp->sk1u pointer are protected
by rtnl_lock. so, rtnl_lock() is added.

Test command:
   gtp-link add gtp1 &
   killall gtp-link
   ip link del gtp1

Splat looks like:
[   83.182767] BUG: KASAN: use-after-free in __lock_acquire+0x3a20/0x46a0
[   83.184128] Read of size 8 at addr ffff8880cc7d5360 by task ip/1008
[   83.185567] CPU: 1 PID: 1008 Comm: ip Not tainted 5.2.0-rc6+ #50
[   83.188469] Call Trace:
[ ... ]
[   83.200126]  lock_acquire+0x141/0x380
[   83.200575]  ? lock_sock_nested+0x3a/0xf0
[   83.201069]  _raw_spin_lock_bh+0x38/0x70
[   83.201551]  ? lock_sock_nested+0x3a/0xf0
[   83.202044]  lock_sock_nested+0x3a/0xf0
[   83.202520]  gtp_encap_destroy+0x18/0xe0 [gtp]
[   83.203065]  gtp_encap_disable.isra.14+0x13/0x50 [gtp]
[   83.203687]  gtp_dellink+0x56/0x170 [gtp]
[   83.204190]  rtnl_delete_link+0xb4/0x100
[ ... ]
[   83.236513] Allocated by task 976:
[   83.236925]  save_stack+0x19/0x80
[   83.237332]  __kasan_kmalloc.constprop.3+0xa0/0xd0
[   83.237894]  kmem_cache_alloc+0xd8/0x280
[   83.238360]  sk_prot_alloc.isra.42+0x50/0x200
[   83.238874]  sk_alloc+0x32/0x940
[   83.239264]  inet_create+0x283/0xc20
[   83.239684]  __sock_create+0x2dd/0x540
[   83.240136]  __sys_socket+0xca/0x1a0
[   83.240550]  __x64_sys_socket+0x6f/0xb0
[   83.240998]  do_syscall_64+0x9c/0x450
[   83.241466]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   83.242061]
[   83.242249] Freed by task 0:
[   83.242616]  save_stack+0x19/0x80
[   83.243013]  __kasan_slab_free+0x111/0x150
[   83.243498]  kmem_cache_free+0x89/0x250
[   83.244444]  __sk_destruct+0x38f/0x5a0
[   83.245366]  rcu_core+0x7e9/0x1c20
[   83.245766]  __do_softirq+0x213/0x8fa

Fixes: 1e3a3ab ("gtp: make GTP sockets in gtp_newlink optional")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
coreosbot pushed a commit that referenced this pull request Jul 26, 2019
[ Upstream commit a2bed90 ]

Current gtp_newlink() could be called after unregister_pernet_subsys().
gtp_newlink() uses gtp_net but it can be destroyed by
unregister_pernet_subsys().
So unregister_pernet_subsys() should be called after
rtnl_link_unregister().

Test commands:
   #SHELL 1
   while :
   do
	   for i in {1..5}
	   do
		./gtp-link add gtp$i &
	   done
	   killall gtp-link
   done

   #SHELL 2
   while :
   do
	modprobe -rv gtp
   done

Splat looks like:
[  753.176631] BUG: KASAN: use-after-free in gtp_newlink+0x9b4/0xa5c [gtp]
[  753.177722] Read of size 8 at addr ffff8880d48f2458 by task gtp-link/7126
[  753.179082] CPU: 0 PID: 7126 Comm: gtp-link Tainted: G        W         5.2.0-rc6+ #50
[  753.185801] Call Trace:
[  753.186264]  dump_stack+0x7c/0xbb
[  753.186863]  ? gtp_newlink+0x9b4/0xa5c [gtp]
[  753.187583]  print_address_description+0xc7/0x240
[  753.188382]  ? gtp_newlink+0x9b4/0xa5c [gtp]
[  753.189097]  ? gtp_newlink+0x9b4/0xa5c [gtp]
[  753.189846]  __kasan_report+0x12a/0x16f
[  753.190542]  ? gtp_newlink+0x9b4/0xa5c [gtp]
[  753.191298]  kasan_report+0xe/0x20
[  753.191893]  gtp_newlink+0x9b4/0xa5c [gtp]
[  753.192580]  ? __netlink_ns_capable+0xc3/0xf0
[  753.193370]  __rtnl_newlink+0xb9f/0x11b0
[ ... ]
[  753.241201] Allocated by task 7186:
[  753.241844]  save_stack+0x19/0x80
[  753.242399]  __kasan_kmalloc.constprop.3+0xa0/0xd0
[  753.243192]  __kmalloc+0x13e/0x300
[  753.243764]  ops_init+0xd6/0x350
[  753.244314]  register_pernet_operations+0x249/0x6f0
[ ... ]
[  753.251770] Freed by task 7178:
[  753.252288]  save_stack+0x19/0x80
[  753.252833]  __kasan_slab_free+0x111/0x150
[  753.253962]  kfree+0xc7/0x280
[  753.254509]  ops_free_list.part.11+0x1c4/0x2d0
[  753.255241]  unregister_pernet_operations+0x262/0x390
[ ... ]
[  753.285883] list_add corruption. next->prev should be prev (ffff8880d48f2458), but was ffff8880d497d878. (next.
[  753.287241] ------------[ cut here ]------------
[  753.287794] kernel BUG at lib/list_debug.c:25!
[  753.288364] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[  753.289099] CPU: 0 PID: 7126 Comm: gtp-link Tainted: G    B   W         5.2.0-rc6+ #50
[  753.291036] RIP: 0010:__list_add_valid+0x74/0xd0
[  753.291589] Code: 48 39 da 75 27 48 39 f5 74 36 48 39 dd 74 31 48 83 c4 08 b8 01 00 00 00 5b 5d c3 48 89 d9 48b
[  753.293779] RSP: 0018:ffff8880cae8f398 EFLAGS: 00010286
[  753.294401] RAX: 0000000000000075 RBX: ffff8880d497d878 RCX: 0000000000000000
[  753.296260] RDX: 0000000000000075 RSI: 0000000000000008 RDI: ffffed10195d1e69
[  753.297070] RBP: ffff8880cd250ae0 R08: ffffed101b4bff21 R09: ffffed101b4bff21
[  753.297899] R10: 0000000000000001 R11: ffffed101b4bff20 R12: ffff8880d497d878
[  753.298703] R13: 0000000000000000 R14: ffff8880cd250ae0 R15: ffff8880d48f2458
[  753.299564] FS:  00007f5f79805740(0000) GS:ffff8880da400000(0000) knlGS:0000000000000000
[  753.300533] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  753.301231] CR2: 00007fe8c7ef4f10 CR3: 00000000b71a6006 CR4: 00000000000606f0
[  753.302183] Call Trace:
[  753.302530]  gtp_newlink+0x5f6/0xa5c [gtp]
[  753.303037]  ? __netlink_ns_capable+0xc3/0xf0
[  753.303576]  __rtnl_newlink+0xb9f/0x11b0
[  753.304092]  ? rtnl_link_unregister+0x230/0x230

Fixes: 459aa66 ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
Signed-off-by: Taehee Yoo <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
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