a29c430393
[ Upstream commit 94dc550a5062030569d4aa76e10e50c8fc001930 ]
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: 459aa660eb1d ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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