3ebc46ca86
In dctcp_update_alpha(), we use a module parameter dctcp_shift_g
as follows:
alpha -= min_not_zero(alpha, alpha >> dctcp_shift_g);
...
delivered_ce <<= (10 - dctcp_shift_g);
It seems syzkaller started fuzzing module parameters and triggered
shift-out-of-bounds [0] by setting 100 to dctcp_shift_g:
memcpy((void*)0x20000080,
"/sys/module/tcp_dctcp/parameters/dctcp_shift_g\000", 47);
res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x20000080ul,
/*flags=*/2ul, /*mode=*/0ul);
memcpy((void*)0x20000000, "100\000", 4);
syscall(__NR_write, /*fd=*/r[0], /*val=*/0x20000000ul, /*len=*/4ul);
Let's limit the max value of dctcp_shift_g by param_set_uint_minmax().
With this patch:
# echo 10 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g
# cat /sys/module/tcp_dctcp/parameters/dctcp_shift_g
10
# echo 11 > /sys/module/tcp_dctcp/parameters/dctcp_shift_g
-bash: echo: write error: Invalid argument
[0]:
UBSAN: shift-out-of-bounds in net/ipv4/tcp_dctcp.c:143:12
shift exponent 100 is too large for 32-bit type 'u32' (aka 'unsigned int')
CPU: 0 PID: 8083 Comm: syz-executor345 Not tainted 6.9.0-05151-g1b294a1f3561 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x201/0x300 lib/dump_stack.c:114
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_shift_out_of_bounds+0x346/0x3a0 lib/ubsan.c:468
dctcp_update_alpha+0x540/0x570 net/ipv4/tcp_dctcp.c:143
tcp_in_ack_event net/ipv4/tcp_input.c:3802 [inline]
tcp_ack+0x17b1/0x3bc0 net/ipv4/tcp_input.c:3948
tcp_rcv_state_process+0x57a/0x2290 net/ipv4/tcp_input.c:6711
tcp_v4_do_rcv+0x764/0xc40 net/ipv4/tcp_ipv4.c:1937
sk_backlog_rcv include/net/sock.h:1106 [inline]
__release_sock+0x20f/0x350 net/core/sock.c:2983
release_sock+0x61/0x1f0 net/core/sock.c:3549
mptcp_subflow_shutdown+0x3d0/0x620 net/mptcp/protocol.c:2907
mptcp_check_send_data_fin+0x225/0x410 net/mptcp/protocol.c:2976
__mptcp_close+0x238/0xad0 net/mptcp/protocol.c:3072
mptcp_close+0x2a/0x1a0 net/mptcp/protocol.c:3127
inet_release+0x190/0x1f0 net/ipv4/af_inet.c:437
__sock_release net/socket.c:659 [inline]
sock_close+0xc0/0x240 net/socket.c:1421
__fput+0x41b/0x890 fs/file_table.c:422
task_work_run+0x23b/0x300 kernel/task_work.c:180
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0x9c8/0x2540 kernel/exit.c:878
do_group_exit+0x201/0x2b0 kernel/exit.c:1027
__do_sys_exit_group kernel/exit.c:1038 [inline]
__se_sys_exit_group kernel/exit.c:1036 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1036
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xe4/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x67/0x6f
RIP: 0033:0x7f6c2b5005b6
Code: Unable to access opcode bytes at 0x7f6c2b50058c.
RSP: 002b:00007ffe883eb948 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f6c2b5862f0 RCX: 00007f6c2b5005b6
RDX: 0000000000000001 RSI: 000000000000003c RDI: 0000000000000001
RBP: 0000000000000001 R08: 00000000000000e7 R09: ffffffffffffffc0
R10: 0000000000000006 R11: 0000000000000246 R12: 00007f6c2b5862f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
</TASK>
Reported-by: syzkaller <syzkaller@googlegroups.com>
Reported-by: Yue Sun <samsun1006219@gmail.com>
Reported-by: xingwei lee <xrivendell7@gmail.com>
Closes: https://lore.kernel.org/netdev/CAEkJfYNJM=cw-8x7_Vmj1J6uYVCWMbbvD=EFmDPVBGpTsqOxEA@mail.gmail.com/
Fixes:
|
||
---|---|---|
.. | ||
netfilter | ||
af_inet.c | ||
ah4.c | ||
arp.c | ||
bpf_tcp_ca.c | ||
cipso_ipv4.c | ||
datagram.c | ||
devinet.c | ||
esp4_offload.c | ||
esp4.c | ||
fib_frontend.c | ||
fib_lookup.h | ||
fib_notifier.c | ||
fib_rules.c | ||
fib_semantics.c | ||
fib_trie.c | ||
fou_bpf.c | ||
fou_core.c | ||
fou_nl.c | ||
fou_nl.h | ||
gre_demux.c | ||
gre_offload.c | ||
icmp.c | ||
igmp.c | ||
inet_connection_sock.c | ||
inet_diag.c | ||
inet_fragment.c | ||
inet_hashtables.c | ||
inet_timewait_sock.c | ||
inetpeer.c | ||
ip_forward.c | ||
ip_fragment.c | ||
ip_gre.c | ||
ip_input.c | ||
ip_options.c | ||
ip_output.c | ||
ip_sockglue.c | ||
ip_tunnel_core.c | ||
ip_tunnel.c | ||
ip_vti.c | ||
ipcomp.c | ||
ipconfig.c | ||
ipip.c | ||
ipmr_base.c | ||
ipmr.c | ||
Kconfig | ||
Makefile | ||
metrics.c | ||
netfilter.c | ||
netlink.c | ||
nexthop.c | ||
ping.c | ||
proc.c | ||
protocol.c | ||
raw_diag.c | ||
raw.c | ||
route.c | ||
syncookies.c | ||
sysctl_net_ipv4.c | ||
tcp_ao.c | ||
tcp_bbr.c | ||
tcp_bic.c | ||
tcp_bpf.c | ||
tcp_cdg.c | ||
tcp_cong.c | ||
tcp_cubic.c | ||
tcp_dctcp.c | ||
tcp_dctcp.h | ||
tcp_diag.c | ||
tcp_fastopen.c | ||
tcp_highspeed.c | ||
tcp_htcp.c | ||
tcp_hybla.c | ||
tcp_illinois.c | ||
tcp_input.c | ||
tcp_ipv4.c | ||
tcp_lp.c | ||
tcp_metrics.c | ||
tcp_minisocks.c | ||
tcp_nv.c | ||
tcp_offload.c | ||
tcp_output.c | ||
tcp_plb.c | ||
tcp_rate.c | ||
tcp_recovery.c | ||
tcp_scalable.c | ||
tcp_sigpool.c | ||
tcp_timer.c | ||
tcp_ulp.c | ||
tcp_vegas.c | ||
tcp_vegas.h | ||
tcp_veno.c | ||
tcp_westwood.c | ||
tcp_yeah.c | ||
tcp.c | ||
tunnel4.c | ||
udp_bpf.c | ||
udp_diag.c | ||
udp_impl.h | ||
udp_offload.c | ||
udp_tunnel_core.c | ||
udp_tunnel_nic.c | ||
udp_tunnel_stub.c | ||
udp.c | ||
udplite.c | ||
xfrm4_input.c | ||
xfrm4_output.c | ||
xfrm4_policy.c | ||
xfrm4_protocol.c | ||
xfrm4_state.c | ||
xfrm4_tunnel.c |