Mubashir Adnan Qureshi
f3217ac2c6
tcp: add support for PLB in DCTCP
...
PLB support is added to TCP DCTCP code. As DCTCP uses ECN as the
congestion signal, PLB also uses ECN to make decisions whether to change
the path or not upon sustained congestion.
Signed-off-by: Mubashir Adnan Qureshi <mubashirq@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Juhyung Park <qkrwngud825@gmail.com>
2024-12-18 15:07:57 +01:00
Eric Dumazet
c8a587ff65
tcp: add accessors to read/set tp->snd_cwnd
...
We had various bugs over the years with code
breaking the assumption that tp->snd_cwnd is greater
than zero.
Lately, syzbot reported the WARN_ON_ONCE(!tp->prior_cwnd) added
in commit 8b8a321ff72c ("tcp: fix zero cwnd in tcp_cwnd_reduction")
can trigger, and without a repro we would have to spend
considerable time finding the bug.
Instead of complaining too late, we want to catch where
and when tp->snd_cwnd is set to an illegal value.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Link: https://lore.kernel.org/r/20220405233538.947344-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Juhyung Park <qkrwngud825@gmail.com>
2024-12-18 15:07:40 +01:00
Kuniyuki Iwashima
bfa7e25b56
tcp: Fix shift-out-of-bounds in dctcp_update_alpha().
...
[ Upstream commit 3ebc46ca8675de6378e3f8f40768e180bb8afa66 ]
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: e3118e8359bb ("net: tcp: add DCTCP congestion control algorithm")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240517091626.32772-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-19 12:27:09 +01:00
