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Taehee Yoo 94dc550a50 gtp: fix an use-after-free in ipv4_pdp_find()
ipv4_pdp_find() is called in TX packet path of GTP.
ipv4_pdp_find() internally uses gtp->tid_hash to lookup pdp context.
In the current code, gtp->tid_hash and gtp->addr_hash are freed by
->dellink(), which is gtp_dellink().
But gtp_dellink() would be called while packets are processing.
So, gtp_dellink() should not free gtp->tid_hash and gtp->addr_hash.
Instead, dev->priv_destructor() would be used because this callback
is called after all packet processing safely.

Test commands:
    ip link add veth1 type veth peer name veth2
    ip a a 172.0.0.1/24 dev veth1
    ip link set veth1 up
    ip a a 172.99.0.1/32 dev lo

    gtp-link add gtp1 &

    gtp-tunnel add gtp1 v1 200 100 172.99.0.2 172.0.0.2
    ip r a  172.99.0.2/32 dev gtp1
    ip link set gtp1 mtu 1500

    ip netns add ns2
    ip link set veth2 netns ns2
    ip netns exec ns2 ip a a 172.0.0.2/24 dev veth2
    ip netns exec ns2 ip link set veth2 up
    ip netns exec ns2 ip a a 172.99.0.2/32 dev lo
    ip netns exec ns2 ip link set lo up

    ip netns exec ns2 gtp-link add gtp2 &
    ip netns exec ns2 gtp-tunnel add gtp2 v1 100 200 172.99.0.1 172.0.0.1
    ip netns exec ns2 ip r a 172.99.0.1/32 dev gtp2
    ip netns exec ns2 ip link set gtp2 mtu 1500

    hping3 172.99.0.2 -2 --flood &
    ip link del gtp1

Splat looks like:
[   72.568081][ T1195] BUG: KASAN: use-after-free in ipv4_pdp_find.isra.12+0x130/0x170 [gtp]
[   72.568916][ T1195] Read of size 8 at addr ffff8880b9a35d28 by task hping3/1195
[   72.569631][ T1195]
[   72.569861][ T1195] CPU: 2 PID: 1195 Comm: hping3 Not tainted 5.5.0-rc1 #199
[   72.570547][ T1195] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
[   72.571438][ T1195] Call Trace:
[   72.571764][ T1195]  dump_stack+0x96/0xdb
[   72.572171][ T1195]  ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp]
[   72.572761][ T1195]  print_address_description.constprop.5+0x1be/0x360
[   72.573400][ T1195]  ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp]
[   72.573971][ T1195]  ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp]
[   72.574544][ T1195]  __kasan_report+0x12a/0x16f
[   72.575014][ T1195]  ? ipv4_pdp_find.isra.12+0x130/0x170 [gtp]
[   72.575593][ T1195]  kasan_report+0xe/0x20
[   72.576004][ T1195]  ipv4_pdp_find.isra.12+0x130/0x170 [gtp]
[   72.576577][ T1195]  gtp_build_skb_ip4+0x199/0x1420 [gtp]
[ ... ]
[   72.647671][ T1195] BUG: unable to handle page fault for address: ffff8880b9a35d28
[   72.648512][ T1195] #PF: supervisor read access in kernel mode
[   72.649158][ T1195] #PF: error_code(0x0000) - not-present page
[   72.649849][ T1195] PGD a6c01067 P4D a6c01067 PUD 11fb07067 PMD 11f939067 PTE 800fffff465ca060
[   72.652958][ T1195] Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[   72.653834][ T1195] CPU: 2 PID: 1195 Comm: hping3 Tainted: G    B             5.5.0-rc1 #199
[   72.668062][ T1195] RIP: 0010:ipv4_pdp_find.isra.12+0x86/0x170 [gtp]
[ ... ]
[   72.679168][ T1195] Call Trace:
[   72.679603][ T1195]  gtp_build_skb_ip4+0x199/0x1420 [gtp]
[   72.681915][ T1195]  ? ipv4_pdp_find.isra.12+0x170/0x170 [gtp]
[   72.682513][ T1195]  ? lock_acquire+0x164/0x3b0
[   72.682966][ T1195]  ? gtp_dev_xmit+0x35e/0x890 [gtp]
[   72.683481][ T1195]  gtp_dev_xmit+0x3c2/0x890 [gtp]
[ ... ]

Fixes: 459aa660eb ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-12-14 17:15:24 -08:00
arch bpf, mips: Limit to 33 tail calls 2019-12-11 13:57:22 +01:00
block block: fix memleak of bio integrity data 2019-12-05 11:38:36 -07:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-11-25 19:49:58 -08:00
Documentation linux-can-fixes-for-5.5-20191208 2019-12-09 09:27:47 -08:00
drivers gtp: fix an use-after-free in ipv4_pdp_find() 2019-12-14 17:15:24 -08:00
fs 9 cifs/smb3 fixes: two timestamp fixes, one oops fix (during oplock break) for stable, two fixes found in multichannel testing, two fixes for file create when using modeforsid mount parm 2019-12-08 12:12:18 -08:00
include tcp: refine tcp_write_queue_empty() implementation 2019-12-13 21:58:40 -08:00
init init/Kconfig: fix indentation 2019-12-04 19:44:13 -08:00
ipc y2038: remove CONFIG_64BIT_TIME 2019-11-15 14:38:27 +01:00
kernel bpf: Make BPF trampoline use register_ftrace_direct() API 2019-12-11 15:18:08 -08:00
lib lib/: fix Kconfig indentation 2019-12-07 11:00:19 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'akpm' (patches from Andrew) 2019-12-05 09:46:26 -08:00
net tcp: refine rule to allow EPOLLOUT generation under mem pressure 2019-12-13 21:58:40 -08:00
samples samples: bpf: fix syscall_tp due to unused syscall 2019-12-11 15:28:06 -08:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-12-08 13:28:11 -08:00
security + Features 2019-12-03 12:51:35 -08:00
sound sound updates #2 for 5.5-rc1 2019-12-06 13:06:14 -08:00
tools selftests/bpf: Test function_graph tracer and bpf trampoline together 2019-12-11 15:19:29 -08:00
usr arch: sembuf.h: make uapi asm/sembuf.h self-contained 2019-12-04 19:44:14 -08:00
virt KVM: Fix jump label out_free_* in kvm_init() 2019-11-23 11:29:17 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap mailmap: add entry for myself 2019-12-13 15:15:33 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Linux 5.4-rc4 2019-10-29 04:43:29 -06:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Add maintainers for rmnet 2019-12-13 15:14:24 -08:00
Makefile Linux 5.5-rc1 2019-12-08 14:57:55 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.