osmocom-net-gprs July 2019

osmocom-net-gprs@lists.osmocom.org

4 participants
30 discussions

RFC: unit tests for kernel GTP module
by Harald Welte 31 Dec '25

31 Dec '25

Dear GTP-interested folks, I would love to somehow get towards some degree of unit testing (or even "continuous integration") for teh kernel GTP code. We currently have the original code in the kernel, we had some recent small fixes and now are getting more patches into place. With relatively few active users out there (and probably none of them in production yet), it's particularly easy to introduce regressions while working on the code. Also, having tested new code even against a test set with limited covrage could help to get more confidence in new patches and thus get them merged sooner. Using tools like sgsnemu of OpenGGSN and the command line tools included in libgtpnl, it should be possibel to cook up some scripts for testing. Even the most basic set of tests would be an improvement over what we have now. One could also think about pcap replay to test with hand-crafted or real-world packets from other GTP implementations. As much as I'd like to put something like this into place myself, I don't think I will be able to work much on this in the near future. The GTP module at this point is a pure hobby and contrary to some years ago while I started it, I don't have any contract work in the GTP area at this point, so other projects currently unfortunately get more attention. So in case somebody among the GTP-interested parties (Travelping, OAI, ...) would want to do something in terms of testing, I'd be more than happy if somebody would step ahead. Otherwise it's all just vapourware going to end up on my ever-growing TODO list :/ Also, if netdev folks have some ideas/pointers about possible frameworks/tools for this kind of testing [it must exist for at least some other kernel networking code?]: Please let me know. I'd be interested to have a look if there's something that can be used as a basis (starting network namespaces, sending/transmitting packets, test case startup/teardown, ...) My "old school" approach would have been to start one or multiple user-mode-linux kernels (those that are to be tested), and then have scripts that set up a gtp socket and gtp tunnels via the libgtp command line tools, and throw packets at that. But I'm sure there must be quite powerful frameworks for that kind of testing in the 21st century? How do other tunneling implementations handle this? Regards, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

4 5

[PATCH AUTOSEL 4.9 73/73] gtp: fix use-after-free in gtp_newlink()
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit a2bed90704c68d3763bf24decb1b781a45395de8 ] 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: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 60df6e391ad2..7e1df403a37d 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -1358,9 +1358,9 @@ late_initcall(gtp_init); static void __exit gtp_fini(void) { - unregister_pernet_subsys(&gtp_net_ops); genl_unregister_family(&gtp_genl_family); rtnl_link_unregister(&gtp_link_ops); + unregister_pernet_subsys(&gtp_net_ops); pr_info("GTP module unloaded\n"); } -- 2.20.1

1 0

[PATCH AUTOSEL 4.9 72/73] gtp: fix Illegal context switch in RCU read-side critical section.
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit 3f167e1921865b379a9becf03828e7202c7b4917 ] 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: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index cb206e5526c4..60df6e391ad2 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -952,7 +952,7 @@ static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info) } - pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL); + pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); if (pctx == NULL) return -ENOMEM; -- 2.20.1

1 0

[PATCH AUTOSEL 4.14 104/105] gtp: fix use-after-free in gtp_newlink()
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit a2bed90704c68d3763bf24decb1b781a45395de8 ] 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: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 53fd66534e3a..5de4053774b8 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -1383,9 +1383,9 @@ late_initcall(gtp_init); static void __exit gtp_fini(void) { - unregister_pernet_subsys(&gtp_net_ops); genl_unregister_family(&gtp_genl_family); rtnl_link_unregister(&gtp_link_ops); + unregister_pernet_subsys(&gtp_net_ops); pr_info("GTP module unloaded\n"); } -- 2.20.1

1 0

[PATCH AUTOSEL 4.14 103/105] gtp: fix use-after-free in gtp_encap_destroy()
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit 1788b8569f5de27da09087fa3f6580d2aa04cc75 ] 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: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index c751f87c935e..53fd66534e3a 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -289,13 +289,17 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) return gtp_rx(pctx, skb, hdrlen, gtp->role); } -static void gtp_encap_destroy(struct sock *sk) +static void __gtp_encap_destroy(struct sock *sk) { struct gtp_dev *gtp; lock_sock(sk); gtp = sk->sk_user_data; if (gtp) { + if (gtp->sk0 == sk) + gtp->sk0 = NULL; + else + gtp->sk1u = NULL; udp_sk(sk)->encap_type = 0; rcu_assign_sk_user_data(sk, NULL); sock_put(sk); @@ -303,12 +307,19 @@ static void gtp_encap_destroy(struct sock *sk) release_sock(sk); } +static void gtp_encap_destroy(struct sock *sk) +{ + rtnl_lock(); + __gtp_encap_destroy(sk); + rtnl_unlock(); +} + static void gtp_encap_disable_sock(struct sock *sk) { if (!sk) return; - gtp_encap_destroy(sk); + __gtp_encap_destroy(sk); } static void gtp_encap_disable(struct gtp_dev *gtp) @@ -1045,6 +1056,7 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) return -EINVAL; } + rtnl_lock(); rcu_read_lock(); gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); @@ -1069,6 +1081,7 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) out_unlock: rcu_read_unlock(); + rtnl_unlock(); return err; } -- 2.20.1

1 0

[PATCH AUTOSEL 4.14 102/105] gtp: fix Illegal context switch in RCU read-side critical section.
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit 3f167e1921865b379a9becf03828e7202c7b4917 ] 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: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 2756edd84abc..c751f87c935e 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -956,7 +956,7 @@ static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk, } - pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL); + pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC); if (pctx == NULL) return -ENOMEM; -- 2.20.1

1 0

[PATCH AUTOSEL 4.14 101/105] gtp: fix suspicious RCU usage
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit e198987e7dd7d3645a53875151cd6f8fc425b706 ] gtp_encap_enable_socket() and gtp_encap_destroy() are not protected by rcu_read_lock(). and it's not safe to write sk->sk_user_data. This patch make these functions to use lock_sock() instead of rcu_dereference_sk_user_data(). Test commands: gtp-link add gtp1 Splat looks like: [ 83.238315] ============================= [ 83.239127] WARNING: suspicious RCU usage [ 83.239702] 5.2.0-rc6+ #49 Not tainted [ 83.240268] ----------------------------- [ 83.241205] drivers/net/gtp.c:799 suspicious rcu_dereference_check() usage! [ 83.243828] [ 83.243828] other info that might help us debug this: [ 83.243828] [ 83.246325] [ 83.246325] rcu_scheduler_active = 2, debug_locks = 1 [ 83.247314] 1 lock held by gtp-link/1008: [ 83.248523] #0: 0000000017772c7f (rtnl_mutex){+.+.}, at: __rtnl_newlink+0x5f5/0x11b0 [ 83.251503] [ 83.251503] stack backtrace: [ 83.252173] CPU: 0 PID: 1008 Comm: gtp-link Not tainted 5.2.0-rc6+ #49 [ 83.253271] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 83.254562] Call Trace: [ 83.254995] dump_stack+0x7c/0xbb [ 83.255567] gtp_encap_enable_socket+0x2df/0x360 [gtp] [ 83.256415] ? gtp_find_dev+0x1a0/0x1a0 [gtp] [ 83.257161] ? memset+0x1f/0x40 [ 83.257843] gtp_newlink+0x90/0xa21 [gtp] [ 83.258497] ? __netlink_ns_capable+0xc3/0xf0 [ 83.259260] __rtnl_newlink+0xb9f/0x11b0 [ 83.260022] ? rtnl_link_unregister+0x230/0x230 [ ... ] Fixes: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index dba3869b61be..2756edd84abc 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -293,12 +293,14 @@ static void gtp_encap_destroy(struct sock *sk) { struct gtp_dev *gtp; - gtp = rcu_dereference_sk_user_data(sk); + lock_sock(sk); + gtp = sk->sk_user_data; if (gtp) { udp_sk(sk)->encap_type = 0; rcu_assign_sk_user_data(sk, NULL); sock_put(sk); } + release_sock(sk); } static void gtp_encap_disable_sock(struct sock *sk) @@ -798,7 +800,8 @@ static struct sock *gtp_encap_enable_socket(int fd, int type, goto out_sock; } - if (rcu_dereference_sk_user_data(sock->sk)) { + lock_sock(sock->sk); + if (sock->sk->sk_user_data) { sk = ERR_PTR(-EBUSY); goto out_sock; } @@ -814,6 +817,7 @@ static struct sock *gtp_encap_enable_socket(int fd, int type, setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg); out_sock: + release_sock(sock->sk); sockfd_put(sock); return sk; } -- 2.20.1

1 0

[PATCH AUTOSEL 4.14 099/105] gtp: add missing gtp_encap_disable_sock() in gtp_encap_enable()
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit e30155fd23c9c141cbe7d99b786e10a83a328837 ] If an invalid role is sent from user space, gtp_encap_enable() will fail. Then, it should call gtp_encap_disable_sock() but current code doesn't. It makes memory leak. Fixes: 91ed81f9abc7 ("gtp: support SGSN-side tunnels") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index f38e32a7ec9c..dba3869b61be 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -845,8 +845,13 @@ static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) if (data[IFLA_GTP_ROLE]) { role = nla_get_u32(data[IFLA_GTP_ROLE]); - if (role > GTP_ROLE_SGSN) + if (role > GTP_ROLE_SGSN) { + if (sk0) + gtp_encap_disable_sock(sk0); + if (sk1u) + gtp_encap_disable_sock(sk1u); return -EINVAL; + } } gtp->sk0 = sk0; -- 2.20.1

1 0

[PATCH AUTOSEL 4.19 157/158] gtp: fix use-after-free in gtp_newlink()
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit a2bed90704c68d3763bf24decb1b781a45395de8 ] 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: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 61e9b288d2dc..d178d5bad7e4 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -1385,9 +1385,9 @@ late_initcall(gtp_init); static void __exit gtp_fini(void) { - unregister_pernet_subsys(&gtp_net_ops); genl_unregister_family(&gtp_genl_family); rtnl_link_unregister(&gtp_link_ops); + unregister_pernet_subsys(&gtp_net_ops); pr_info("GTP module unloaded\n"); } -- 2.20.1

1 0

[PATCH AUTOSEL 4.19 156/158] gtp: fix use-after-free in gtp_encap_destroy()
by Sasha Levin 15 Jul '19

15 Jul '19

From: Taehee Yoo <ap420073(a)gmail.com> [ Upstream commit 1788b8569f5de27da09087fa3f6580d2aa04cc75 ] 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: 1e3a3abd8b28 ("gtp: make GTP sockets in gtp_newlink optional") Signed-off-by: Taehee Yoo <ap420073(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/net/gtp.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index 6f1ad7ccaea6..61e9b288d2dc 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -289,13 +289,17 @@ static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) return gtp_rx(pctx, skb, hdrlen, gtp->role); } -static void gtp_encap_destroy(struct sock *sk) +static void __gtp_encap_destroy(struct sock *sk) { struct gtp_dev *gtp; lock_sock(sk); gtp = sk->sk_user_data; if (gtp) { + if (gtp->sk0 == sk) + gtp->sk0 = NULL; + else + gtp->sk1u = NULL; udp_sk(sk)->encap_type = 0; rcu_assign_sk_user_data(sk, NULL); sock_put(sk); @@ -303,12 +307,19 @@ static void gtp_encap_destroy(struct sock *sk) release_sock(sk); } +static void gtp_encap_destroy(struct sock *sk) +{ + rtnl_lock(); + __gtp_encap_destroy(sk); + rtnl_unlock(); +} + static void gtp_encap_disable_sock(struct sock *sk) { if (!sk) return; - gtp_encap_destroy(sk); + __gtp_encap_destroy(sk); } static void gtp_encap_disable(struct gtp_dev *gtp) @@ -1047,6 +1058,7 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) return -EINVAL; } + rtnl_lock(); rcu_read_lock(); gtp = gtp_find_dev(sock_net(skb->sk), info->attrs); @@ -1071,6 +1083,7 @@ static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) out_unlock: rcu_read_unlock(); + rtnl_unlock(); return err; } -- 2.20.1

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osmocom-net-gprs July 2019