* [PATCH net] inet: clear num_timeout reqsk_alloc()
@ 2019-06-19 16:38 Eric Dumazet
2019-06-19 16:45 ` Soheil Hassas Yeganeh
2019-06-19 21:48 ` David Miller
0 siblings, 2 replies; 4+ messages in thread
From: Eric Dumazet @ 2019-06-19 16:38 UTC (permalink / raw)
To: David S . Miller
Cc: netdev, Eric Dumazet, Eric Dumazet, Yuchung Cheng, Neal Cardwell,
Soheil Hassas Yeganeh, syzbot
KMSAN caught uninit-value in tcp_create_openreq_child() [1]
This is caused by a recent change, combined by the fact
that TCP cleared num_timeout, num_retrans and sk fields only
when a request socket was about to be queued.
Under syncookie mode, a temporary request socket is used,
and req->num_timeout could contain garbage.
Lets clear these three fields sooner, there is really no
point trying to defer this and risk other bugs.
[1]
BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x191/0x1f0 lib/dump_stack.c:113
kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611
__msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152
tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209
cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252
tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
dst_input include/net/dst.h:439 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
__netif_receive_skb_one_core net/core/dev.c:4981 [inline]
__netif_receive_skb net/core/dev.c:5095 [inline]
process_backlog+0x721/0x1410 net/core/dev.c:5906
napi_poll net/core/dev.c:6329 [inline]
net_rx_action+0x738/0x1940 net/core/dev.c:6395
__do_softirq+0x4ad/0x858 kernel/softirq.c:293
do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
</IRQ>
do_softirq kernel/softirq.c:338 [inline]
__local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
dst_output include/net/dst.h:433 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
__tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
__tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
__sock_release net/socket.c:601 [inline]
sock_close+0x156/0x490 net/socket.c:1273
__fput+0x4c9/0xba0 fs/file_table.c:280
____fput+0x37/0x40 fs/file_table.c:313
task_work_run+0x22e/0x2a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:185 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x401d50
Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00
RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50
RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c
R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0
R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000
Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160
kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781
reqsk_alloc include/net/request_sock.h:84 [inline]
inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384
cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173
tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
dst_input include/net/dst.h:439 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
__netif_receive_skb_one_core net/core/dev.c:4981 [inline]
__netif_receive_skb net/core/dev.c:5095 [inline]
process_backlog+0x721/0x1410 net/core/dev.c:5906
napi_poll net/core/dev.c:6329 [inline]
net_rx_action+0x738/0x1940 net/core/dev.c:6395
__do_softirq+0x4ad/0x858 kernel/softirq.c:293
do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
do_softirq kernel/softirq.c:338 [inline]
__local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
dst_output include/net/dst.h:433 [inline]
NF_HOOK include/linux/netfilter.h:305 [inline]
ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
__tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
__tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
__sock_release net/socket.c:601 [inline]
sock_close+0x156/0x490 net/socket.c:1273
__fput+0x4c9/0xba0 fs/file_table.c:280
____fput+0x37/0x40 fs/file_table.c:313
task_work_run+0x22e/0x2a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:185 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
entry_SYSCALL_64_after_hwframe+0x63/0xe7
Fixes: 336c39a03151 ("tcp: undo init congestion window on false SYNACK timeout")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
---
include/net/request_sock.h | 3 +++
net/ipv4/inet_connection_sock.c | 4 ----
net/ipv4/tcp_fastopen.c | 4 ----
3 files changed, 3 insertions(+), 8 deletions(-)
diff --git a/include/net/request_sock.h b/include/net/request_sock.h
index b3ea21f2732ef509d47bfcecc38f78d9178a3d5c..fd178d58fa84e7ae7abdeff5be2ba7b1ec790889 100644
--- a/include/net/request_sock.h
+++ b/include/net/request_sock.h
@@ -97,6 +97,9 @@ reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener,
sk_node_init(&req_to_sk(req)->sk_node);
sk_tx_queue_clear(req_to_sk(req));
req->saved_syn = NULL;
+ req->num_timeout = 0;
+ req->num_retrans = 0;
+ req->sk = NULL;
refcount_set(&req->rsk_refcnt, 0);
return req;
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 13ec7c3a9c49f02ed359f3f941c8ff70f4699695..7fd6db3fe3664b02fa0279a6aef08144588de6e4 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -752,10 +752,6 @@ static void reqsk_timer_handler(struct timer_list *t)
static void reqsk_queue_hash_req(struct request_sock *req,
unsigned long timeout)
{
- req->num_retrans = 0;
- req->num_timeout = 0;
- req->sk = NULL;
-
timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
mod_timer(&req->rsk_timer, jiffies + timeout);
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index 018a484773551f8e67fe20be97b04f6d02104a56..f5a45e1e118224966e336725de71d3636b207892 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -221,10 +221,6 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
struct sock *child;
bool own_req;
- req->num_retrans = 0;
- req->num_timeout = 0;
- req->sk = NULL;
-
child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
NULL, &own_req);
if (!child)
--
2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH net] inet: clear num_timeout reqsk_alloc()
2019-06-19 16:38 [PATCH net] inet: clear num_timeout reqsk_alloc() Eric Dumazet
@ 2019-06-19 16:45 ` Soheil Hassas Yeganeh
2019-06-19 16:57 ` Yuchung Cheng
2019-06-19 21:48 ` David Miller
1 sibling, 1 reply; 4+ messages in thread
From: Soheil Hassas Yeganeh @ 2019-06-19 16:45 UTC (permalink / raw)
To: Eric Dumazet
Cc: David S . Miller, netdev, Eric Dumazet, Yuchung Cheng,
Neal Cardwell, syzbot
On Wed, Jun 19, 2019 at 12:38 PM Eric Dumazet <edumazet@google.com> wrote:
>
> KMSAN caught uninit-value in tcp_create_openreq_child() [1]
> This is caused by a recent change, combined by the fact
> that TCP cleared num_timeout, num_retrans and sk fields only
> when a request socket was about to be queued.
>
> Under syncookie mode, a temporary request socket is used,
> and req->num_timeout could contain garbage.
>
> Lets clear these three fields sooner, there is really no
> point trying to defer this and risk other bugs.
>
> [1]
>
> BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
> CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> <IRQ>
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x191/0x1f0 lib/dump_stack.c:113
> kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611
> __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
> tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
> tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152
> tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209
> cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252
> tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
> tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
> tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
> ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
> ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
> NF_HOOK include/linux/netfilter.h:305 [inline]
> ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
> dst_input include/net/dst.h:439 [inline]
> ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
> NF_HOOK include/linux/netfilter.h:305 [inline]
> ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
> __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
> __netif_receive_skb net/core/dev.c:5095 [inline]
> process_backlog+0x721/0x1410 net/core/dev.c:5906
> napi_poll net/core/dev.c:6329 [inline]
> net_rx_action+0x738/0x1940 net/core/dev.c:6395
> __do_softirq+0x4ad/0x858 kernel/softirq.c:293
> do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
> </IRQ>
> do_softirq kernel/softirq.c:338 [inline]
> __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
> local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
> rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
> ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
> ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
> NF_HOOK_COND include/linux/netfilter.h:294 [inline]
> ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
> dst_output include/net/dst.h:433 [inline]
> NF_HOOK include/linux/netfilter.h:305 [inline]
> ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
> inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
> __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
> tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
> tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
> __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
> tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
> tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
> inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
> inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
> __sock_release net/socket.c:601 [inline]
> sock_close+0x156/0x490 net/socket.c:1273
> __fput+0x4c9/0xba0 fs/file_table.c:280
> ____fput+0x37/0x40 fs/file_table.c:313
> task_work_run+0x22e/0x2a0 kernel/task_work.c:113
> tracehook_notify_resume include/linux/tracehook.h:185 [inline]
> exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
> prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
> syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
> do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
> entry_SYSCALL_64_after_hwframe+0x63/0xe7
> RIP: 0033:0x401d50
> Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00
> RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
> RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50
> RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003
> RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c
> R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0
> R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000
>
> Uninit was created at:
> kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
> kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160
> kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
> kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781
> reqsk_alloc include/net/request_sock.h:84 [inline]
> inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384
> cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173
> tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
> tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
> tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
> ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
> ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
> NF_HOOK include/linux/netfilter.h:305 [inline]
> ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
> dst_input include/net/dst.h:439 [inline]
> ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
> NF_HOOK include/linux/netfilter.h:305 [inline]
> ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
> __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
> __netif_receive_skb net/core/dev.c:5095 [inline]
> process_backlog+0x721/0x1410 net/core/dev.c:5906
> napi_poll net/core/dev.c:6329 [inline]
> net_rx_action+0x738/0x1940 net/core/dev.c:6395
> __do_softirq+0x4ad/0x858 kernel/softirq.c:293
> do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
> do_softirq kernel/softirq.c:338 [inline]
> __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
> local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
> rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
> ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
> ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
> NF_HOOK_COND include/linux/netfilter.h:294 [inline]
> ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
> dst_output include/net/dst.h:433 [inline]
> NF_HOOK include/linux/netfilter.h:305 [inline]
> ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
> inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
> __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
> tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
> tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
> __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
> tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
> tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
> inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
> inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
> __sock_release net/socket.c:601 [inline]
> sock_close+0x156/0x490 net/socket.c:1273
> __fput+0x4c9/0xba0 fs/file_table.c:280
> ____fput+0x37/0x40 fs/file_table.c:313
> task_work_run+0x22e/0x2a0 kernel/task_work.c:113
> tracehook_notify_resume include/linux/tracehook.h:185 [inline]
> exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
> prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
> syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
> do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
> entry_SYSCALL_64_after_hwframe+0x63/0xe7
>
> Fixes: 336c39a03151 ("tcp: undo init congestion window on false SYNACK timeout")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Yuchung Cheng <ycheng@google.com>
> Cc: Neal Cardwell <ncardwell@google.com>
> Cc: Soheil Hassas Yeganeh <soheil@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Thank you for the fix!
> ---
> include/net/request_sock.h | 3 +++
> net/ipv4/inet_connection_sock.c | 4 ----
> net/ipv4/tcp_fastopen.c | 4 ----
> 3 files changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/include/net/request_sock.h b/include/net/request_sock.h
> index b3ea21f2732ef509d47bfcecc38f78d9178a3d5c..fd178d58fa84e7ae7abdeff5be2ba7b1ec790889 100644
> --- a/include/net/request_sock.h
> +++ b/include/net/request_sock.h
> @@ -97,6 +97,9 @@ reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener,
> sk_node_init(&req_to_sk(req)->sk_node);
> sk_tx_queue_clear(req_to_sk(req));
> req->saved_syn = NULL;
> + req->num_timeout = 0;
> + req->num_retrans = 0;
> + req->sk = NULL;
> refcount_set(&req->rsk_refcnt, 0);
>
> return req;
> diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
> index 13ec7c3a9c49f02ed359f3f941c8ff70f4699695..7fd6db3fe3664b02fa0279a6aef08144588de6e4 100644
> --- a/net/ipv4/inet_connection_sock.c
> +++ b/net/ipv4/inet_connection_sock.c
> @@ -752,10 +752,6 @@ static void reqsk_timer_handler(struct timer_list *t)
> static void reqsk_queue_hash_req(struct request_sock *req,
> unsigned long timeout)
> {
> - req->num_retrans = 0;
> - req->num_timeout = 0;
> - req->sk = NULL;
> -
> timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
> mod_timer(&req->rsk_timer, jiffies + timeout);
>
> diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
> index 018a484773551f8e67fe20be97b04f6d02104a56..f5a45e1e118224966e336725de71d3636b207892 100644
> --- a/net/ipv4/tcp_fastopen.c
> +++ b/net/ipv4/tcp_fastopen.c
> @@ -221,10 +221,6 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
> struct sock *child;
> bool own_req;
>
> - req->num_retrans = 0;
> - req->num_timeout = 0;
> - req->sk = NULL;
> -
> child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
> NULL, &own_req);
> if (!child)
> --
> 2.22.0.410.gd8fdbe21b5-goog
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH net] inet: clear num_timeout reqsk_alloc()
2019-06-19 16:45 ` Soheil Hassas Yeganeh
@ 2019-06-19 16:57 ` Yuchung Cheng
0 siblings, 0 replies; 4+ messages in thread
From: Yuchung Cheng @ 2019-06-19 16:57 UTC (permalink / raw)
To: Soheil Hassas Yeganeh
Cc: Eric Dumazet, David S . Miller, netdev, Eric Dumazet,
Neal Cardwell, syzbot
On Wed, Jun 19, 2019 at 9:46 AM Soheil Hassas Yeganeh <soheil@google.com> wrote:
>
> On Wed, Jun 19, 2019 at 12:38 PM Eric Dumazet <edumazet@google.com> wrote:
> >
> > KMSAN caught uninit-value in tcp_create_openreq_child() [1]
> > This is caused by a recent change, combined by the fact
> > that TCP cleared num_timeout, num_retrans and sk fields only
> > when a request socket was about to be queued.
> >
> > Under syncookie mode, a temporary request socket is used,
> > and req->num_timeout could contain garbage.
> >
> > Lets clear these three fields sooner, there is really no
> > point trying to defer this and risk other bugs.
> >
> > [1]
> >
> > BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
> > CPU: 1 PID: 13357 Comm: syz-executor591 Not tainted 5.2.0-rc4+ #3
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> > Call Trace:
> > <IRQ>
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0x191/0x1f0 lib/dump_stack.c:113
> > kmsan_report+0x162/0x2d0 mm/kmsan/kmsan.c:611
> > __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:304
> > tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
> > tcp_v6_syn_recv_sock+0x761/0x2d80 net/ipv6/tcp_ipv6.c:1152
> > tcp_get_cookie_sock+0x16e/0x6b0 net/ipv4/syncookies.c:209
> > cookie_v6_check+0x27e0/0x29a0 net/ipv6/syncookies.c:252
> > tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
> > tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
> > tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
> > ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
> > ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
> > NF_HOOK include/linux/netfilter.h:305 [inline]
> > ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
> > dst_input include/net/dst.h:439 [inline]
> > ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
> > NF_HOOK include/linux/netfilter.h:305 [inline]
> > ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
> > __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
> > __netif_receive_skb net/core/dev.c:5095 [inline]
> > process_backlog+0x721/0x1410 net/core/dev.c:5906
> > napi_poll net/core/dev.c:6329 [inline]
> > net_rx_action+0x738/0x1940 net/core/dev.c:6395
> > __do_softirq+0x4ad/0x858 kernel/softirq.c:293
> > do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
> > </IRQ>
> > do_softirq kernel/softirq.c:338 [inline]
> > __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
> > local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
> > rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
> > ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
> > ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
> > NF_HOOK_COND include/linux/netfilter.h:294 [inline]
> > ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
> > dst_output include/net/dst.h:433 [inline]
> > NF_HOOK include/linux/netfilter.h:305 [inline]
> > ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
> > inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
> > __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
> > tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
> > tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
> > __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
> > tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
> > tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
> > inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
> > inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
> > __sock_release net/socket.c:601 [inline]
> > sock_close+0x156/0x490 net/socket.c:1273
> > __fput+0x4c9/0xba0 fs/file_table.c:280
> > ____fput+0x37/0x40 fs/file_table.c:313
> > task_work_run+0x22e/0x2a0 kernel/task_work.c:113
> > tracehook_notify_resume include/linux/tracehook.h:185 [inline]
> > exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
> > prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
> > syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
> > do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
> > entry_SYSCALL_64_after_hwframe+0x63/0xe7
> > RIP: 0033:0x401d50
> > Code: 01 f0 ff ff 0f 83 40 0d 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d dd 8d 2d 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 14 0d 00 00 c3 48 83 ec 08 e8 7a 02 00 00
> > RSP: 002b:00007fff1cf58cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
> > RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000401d50
> > RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000003
> > RBP: 00000000004a9050 R08: 0000000020000040 R09: 000000000000001c
> > R10: 0000000020004004 R11: 0000000000000246 R12: 0000000000402ef0
> > R13: 0000000000402f80 R14: 0000000000000000 R15: 0000000000000000
> >
> > Uninit was created at:
> > kmsan_save_stack_with_flags mm/kmsan/kmsan.c:201 [inline]
> > kmsan_internal_poison_shadow+0x53/0xa0 mm/kmsan/kmsan.c:160
> > kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
> > kmem_cache_alloc+0x534/0xb00 mm/slub.c:2781
> > reqsk_alloc include/net/request_sock.h:84 [inline]
> > inet_reqsk_alloc+0xa8/0x600 net/ipv4/tcp_input.c:6384
> > cookie_v6_check+0xadb/0x29a0 net/ipv6/syncookies.c:173
> > tcp_v6_cookie_check net/ipv6/tcp_ipv6.c:1039 [inline]
> > tcp_v6_do_rcv+0xf1c/0x1ce0 net/ipv6/tcp_ipv6.c:1344
> > tcp_v6_rcv+0x60b7/0x6a30 net/ipv6/tcp_ipv6.c:1554
> > ip6_protocol_deliver_rcu+0x1433/0x22f0 net/ipv6/ip6_input.c:397
> > ip6_input_finish net/ipv6/ip6_input.c:438 [inline]
> > NF_HOOK include/linux/netfilter.h:305 [inline]
> > ip6_input+0x2af/0x340 net/ipv6/ip6_input.c:447
> > dst_input include/net/dst.h:439 [inline]
> > ip6_rcv_finish net/ipv6/ip6_input.c:76 [inline]
> > NF_HOOK include/linux/netfilter.h:305 [inline]
> > ipv6_rcv+0x683/0x710 net/ipv6/ip6_input.c:272
> > __netif_receive_skb_one_core net/core/dev.c:4981 [inline]
> > __netif_receive_skb net/core/dev.c:5095 [inline]
> > process_backlog+0x721/0x1410 net/core/dev.c:5906
> > napi_poll net/core/dev.c:6329 [inline]
> > net_rx_action+0x738/0x1940 net/core/dev.c:6395
> > __do_softirq+0x4ad/0x858 kernel/softirq.c:293
> > do_softirq_own_stack+0x49/0x80 arch/x86/entry/entry_64.S:1052
> > do_softirq kernel/softirq.c:338 [inline]
> > __local_bh_enable_ip+0x199/0x1e0 kernel/softirq.c:190
> > local_bh_enable+0x36/0x40 include/linux/bottom_half.h:32
> > rcu_read_unlock_bh include/linux/rcupdate.h:682 [inline]
> > ip6_finish_output2+0x213f/0x2670 net/ipv6/ip6_output.c:117
> > ip6_finish_output+0xae4/0xbc0 net/ipv6/ip6_output.c:150
> > NF_HOOK_COND include/linux/netfilter.h:294 [inline]
> > ip6_output+0x5d3/0x720 net/ipv6/ip6_output.c:167
> > dst_output include/net/dst.h:433 [inline]
> > NF_HOOK include/linux/netfilter.h:305 [inline]
> > ip6_xmit+0x1f53/0x2650 net/ipv6/ip6_output.c:271
> > inet6_csk_xmit+0x3df/0x4f0 net/ipv6/inet6_connection_sock.c:135
> > __tcp_transmit_skb+0x4076/0x5b40 net/ipv4/tcp_output.c:1156
> > tcp_transmit_skb net/ipv4/tcp_output.c:1172 [inline]
> > tcp_write_xmit+0x39a9/0xa730 net/ipv4/tcp_output.c:2397
> > __tcp_push_pending_frames+0x124/0x4e0 net/ipv4/tcp_output.c:2573
> > tcp_send_fin+0xd43/0x1540 net/ipv4/tcp_output.c:3118
> > tcp_close+0x16ba/0x1860 net/ipv4/tcp.c:2403
> > inet_release+0x1f7/0x270 net/ipv4/af_inet.c:427
> > inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:470
> > __sock_release net/socket.c:601 [inline]
> > sock_close+0x156/0x490 net/socket.c:1273
> > __fput+0x4c9/0xba0 fs/file_table.c:280
> > ____fput+0x37/0x40 fs/file_table.c:313
> > task_work_run+0x22e/0x2a0 kernel/task_work.c:113
> > tracehook_notify_resume include/linux/tracehook.h:185 [inline]
> > exit_to_usermode_loop arch/x86/entry/common.c:168 [inline]
> > prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:199
> > syscall_return_slowpath+0x90/0x5c0 arch/x86/entry/common.c:279
> > do_syscall_64+0xe2/0xf0 arch/x86/entry/common.c:305
> > entry_SYSCALL_64_after_hwframe+0x63/0xe7
> >
> > Fixes: 336c39a03151 ("tcp: undo init congestion window on false SYNACK timeout")
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
> > Cc: Yuchung Cheng <ycheng@google.com>
> > Cc: Neal Cardwell <ncardwell@google.com>
> > Cc: Soheil Hassas Yeganeh <soheil@google.com>
> > Reported-by: syzbot <syzkaller@googlegroups.com>
>
> Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
>
> Thank you for the fix!
Acked-by: Yuchung Cheng <ycheng@google.com>
Thanks for fixing it!
>
> > ---
> > include/net/request_sock.h | 3 +++
> > net/ipv4/inet_connection_sock.c | 4 ----
> > net/ipv4/tcp_fastopen.c | 4 ----
> > 3 files changed, 3 insertions(+), 8 deletions(-)
> >
> > diff --git a/include/net/request_sock.h b/include/net/request_sock.h
> > index b3ea21f2732ef509d47bfcecc38f78d9178a3d5c..fd178d58fa84e7ae7abdeff5be2ba7b1ec790889 100644
> > --- a/include/net/request_sock.h
> > +++ b/include/net/request_sock.h
> > @@ -97,6 +97,9 @@ reqsk_alloc(const struct request_sock_ops *ops, struct sock *sk_listener,
> > sk_node_init(&req_to_sk(req)->sk_node);
> > sk_tx_queue_clear(req_to_sk(req));
> > req->saved_syn = NULL;
> > + req->num_timeout = 0;
> > + req->num_retrans = 0;
> > + req->sk = NULL;
> > refcount_set(&req->rsk_refcnt, 0);
> >
> > return req;
> > diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
> > index 13ec7c3a9c49f02ed359f3f941c8ff70f4699695..7fd6db3fe3664b02fa0279a6aef08144588de6e4 100644
> > --- a/net/ipv4/inet_connection_sock.c
> > +++ b/net/ipv4/inet_connection_sock.c
> > @@ -752,10 +752,6 @@ static void reqsk_timer_handler(struct timer_list *t)
> > static void reqsk_queue_hash_req(struct request_sock *req,
> > unsigned long timeout)
> > {
> > - req->num_retrans = 0;
> > - req->num_timeout = 0;
> > - req->sk = NULL;
> > -
> > timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED);
> > mod_timer(&req->rsk_timer, jiffies + timeout);
> >
> > diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
> > index 018a484773551f8e67fe20be97b04f6d02104a56..f5a45e1e118224966e336725de71d3636b207892 100644
> > --- a/net/ipv4/tcp_fastopen.c
> > +++ b/net/ipv4/tcp_fastopen.c
> > @@ -221,10 +221,6 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
> > struct sock *child;
> > bool own_req;
> >
> > - req->num_retrans = 0;
> > - req->num_timeout = 0;
> > - req->sk = NULL;
> > -
> > child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
> > NULL, &own_req);
> > if (!child)
> > --
> > 2.22.0.410.gd8fdbe21b5-goog
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net] inet: clear num_timeout reqsk_alloc()
2019-06-19 16:38 [PATCH net] inet: clear num_timeout reqsk_alloc() Eric Dumazet
2019-06-19 16:45 ` Soheil Hassas Yeganeh
@ 2019-06-19 21:48 ` David Miller
1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2019-06-19 21:48 UTC (permalink / raw)
To: edumazet; +Cc: netdev, eric.dumazet, ycheng, ncardwell, soheil, syzkaller
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 19 Jun 2019 09:38:38 -0700
> KMSAN caught uninit-value in tcp_create_openreq_child() [1]
> This is caused by a recent change, combined by the fact
> that TCP cleared num_timeout, num_retrans and sk fields only
> when a request socket was about to be queued.
>
> Under syncookie mode, a temporary request socket is used,
> and req->num_timeout could contain garbage.
>
> Lets clear these three fields sooner, there is really no
> point trying to defer this and risk other bugs.
>
> [1]
>
> BUG: KMSAN: uninit-value in tcp_create_openreq_child+0x157f/0x1cc0 net/ipv4/tcp_minisocks.c:526
...
> Fixes: 336c39a03151 ("tcp: undo init congestion window on false SYNACK timeout")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Yuchung Cheng <ycheng@google.com>
> Cc: Neal Cardwell <ncardwell@google.com>
> Cc: Soheil Hassas Yeganeh <soheil@google.com>
> Reported-by: syzbot <syzkaller@googlegroups.com>
Applied, thanks Eric.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-06-19 21:48 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-06-19 16:38 [PATCH net] inet: clear num_timeout reqsk_alloc() Eric Dumazet
2019-06-19 16:45 ` Soheil Hassas Yeganeh
2019-06-19 16:57 ` Yuchung Cheng
2019-06-19 21:48 ` David Miller
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