[PATCH 3.16 123/366] soreuseport: initialise timewait reuseport field

Ben Hutchings
2018-10-14T23:37:20Z

From: Eric Dumazet <edumazet@google.com>

commit 3099a52918937ab86ec47038ad80d377ba16c531 upstream.

syzbot reported an uninit-value in inet_csk_bind_conflict() [1]

It turns out we never propagated sk->sk_reuseport into timewait socket.

[1]
BUG: KMSAN: uninit-value in inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151
CPU: 1 PID: 3589 Comm: syzkaller008242 Not tainted 4.16.0+ #82
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
inet_csk_bind_conflict+0x5f9/0x990 net/ipv4/inet_connection_sock.c:151
inet_csk_get_port+0x1d28/0x1e40 net/ipv4/inet_connection_sock.c:320
inet6_bind+0x121c/0x1820 net/ipv6/af_inet6.c:399
SYSC_bind+0x3f2/0x4b0 net/socket.c:1474
SyS_bind+0x54/0x80 net/socket.c:1460
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x4416e9
RSP: 002b:00007ffce6d15c88 EFLAGS: 00000217 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0100000000000000 RCX: 00000000004416e9
RDX: 000000000000001c RSI: 0000000020402000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00000000e6d15e08 R09: 00000000e6d15e08
R10: 0000000000000004 R11: 0000000000000217 R12: 0000000000009478
R13: 00000000006cd448 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
__msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
tcp_time_wait+0xf17/0xf50 net/ipv4/tcp_minisocks.c:283
tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
sk_backlog_rcv include/net/sock.h:908 [inline]
__release_sock+0x2d6/0x680 net/core/sock.c:2271
release_sock+0x97/0x2a0 net/core/sock.c:2786
tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
sock_release net/socket.c:595 [inline]
sock_close+0xe0/0x300 net/socket.c:1149
__fput+0x49e/0xa10 fs/file_table.c:209
____fput+0x37/0x40 fs/file_table.c:243
task_work_run+0x243/0x2c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x10e1/0x38d0 kernel/exit.c:867
do_group_exit+0x1a0/0x360 kernel/exit.c:970
SYSC_exit_group+0x21/0x30 kernel/exit.c:981
SyS_exit_group+0x25/0x30 kernel/exit.c:979
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:293 [inline]
kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:684
__msan_chain_origin+0x69/0xc0 mm/kmsan/kmsan_instr.c:521
inet_twsk_alloc+0xaef/0xc00 net/ipv4/inet_timewait_sock.c:182
tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258
tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
sk_backlog_rcv include/net/sock.h:908 [inline]
__release_sock+0x2d6/0x680 net/core/sock.c:2271
release_sock+0x97/0x2a0 net/core/sock.c:2786
tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
sock_release net/socket.c:595 [inline]
sock_close+0xe0/0x300 net/socket.c:1149
__fput+0x49e/0xa10 fs/file_table.c:209
____fput+0x37/0x40 fs/file_table.c:243
task_work_run+0x243/0x2c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x10e1/0x38d0 kernel/exit.c:867
do_group_exit+0x1a0/0x360 kernel/exit.c:970
SYSC_exit_group+0x21/0x30 kernel/exit.c:981
SyS_exit_group+0x25/0x30 kernel/exit.c:979
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188
kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314
kmem_cache_alloc+0xaab/0xb90 mm/slub.c:2756
inet_twsk_alloc+0x13b/0xc00 net/ipv4/inet_timewait_sock.c:163
tcp_time_wait+0xd9/0xf50 net/ipv4/tcp_minisocks.c:258
tcp_rcv_state_process+0xebe/0x6490 net/ipv4/tcp_input.c:6003
tcp_v6_do_rcv+0x11dd/0x1d90 net/ipv6/tcp_ipv6.c:1331
sk_backlog_rcv include/net/sock.h:908 [inline]
__release_sock+0x2d6/0x680 net/core/sock.c:2271
release_sock+0x97/0x2a0 net/core/sock.c:2786
tcp_close+0x277/0x18f0 net/ipv4/tcp.c:2269
inet_release+0x240/0x2a0 net/ipv4/af_inet.c:427
inet6_release+0xaf/0x100 net/ipv6/af_inet6.c:435
sock_release net/socket.c:595 [inline]
sock_close+0xe0/0x300 net/socket.c:1149
__fput+0x49e/0xa10 fs/file_table.c:209
____fput+0x37/0x40 fs/file_table.c:243
task_work_run+0x243/0x2c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x10e1/0x38d0 kernel/exit.c:867
do_group_exit+0x1a0/0x360 kernel/exit.c:970
SYSC_exit_group+0x21/0x30 kernel/exit.c:981
SyS_exit_group+0x25/0x30 kernel/exit.c:979
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2

Fixes: da5e36308d9f ("soreuseport: TCP/IPv4 implementation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
include/net/inet_timewait_sock.h | 1 +
net/ipv4/inet_timewait_sock.c | 1 +
2 files changed, 2 insertions(+)

--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -108,6 +108,7 @@ struct inet_timewait_sock {
#define tw_family __tw_common.skc_family
#define tw_state __tw_common.skc_state
#define tw_reuse __tw_common.skc_reuse
+#define tw_reuseport __tw_common.skc_reuseport
#define tw_bound_dev_if __tw_common.skc_bound_dev_if
#define tw_node __tw_common.skc_nulls_node
#define tw_bind_node __tw_common.skc_bind_node
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -191,6 +191,7 @@ struct inet_timewait_sock *inet_twsk_all
tw->tw_dport = inet->inet_dport;
tw->tw_family = sk->sk_family;
tw->tw_reuse = sk->sk_reuse;
+ tw->tw_reuseport = sk->sk_reuseport;
tw->tw_hash = sk->sk_hash;
tw->tw_ipv6only = 0;
tw->tw_transparent = inet->transparent;