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authorYueHaibing <yuehaibing@huawei.com>2023-04-06 14:34:50 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-20 12:10:26 +0200
commita069d4d98cd271a70b561cb757485efe5f5e5a7e (patch)
treec15a9720c8afed8f122988438c1f8b1209360a8b
parentcc9f9a49f5b3b7bd70e8f7edd10b4f9be196aff3 (diff)
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tcp: restrict net.ipv4.tcp_app_win
[ Upstream commit dc5110c2d959c1707e12df5f792f41d90614adaa ] UBSAN: shift-out-of-bounds in net/ipv4/tcp_input.c:555:23 shift exponent 255 is too large for 32-bit type 'int' CPU: 1 PID: 7907 Comm: ssh Not tainted 6.3.0-rc4-00161-g62bad54b26db-dirty #206 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x136/0x150 __ubsan_handle_shift_out_of_bounds+0x21f/0x5a0 tcp_init_transfer.cold+0x3a/0xb9 tcp_finish_connect+0x1d0/0x620 tcp_rcv_state_process+0xd78/0x4d60 tcp_v4_do_rcv+0x33d/0x9d0 __release_sock+0x133/0x3b0 release_sock+0x58/0x1b0 'maxwin' is int, shifting int for 32 or more bits is undefined behaviour. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--Documentation/networking/ip-sysctl.rst2
-rw-r--r--net/ipv4/sysctl_net_ipv4.c3
2 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 0158dff63887..df26cf4110ef 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -272,6 +272,8 @@ tcp_app_win - INTEGER
Reserve max(window/2^tcp_app_win, mss) of window for application
buffer. Value 0 is special, it means that nothing is reserved.
+ Possible values are [0, 31], inclusive.
+
Default: 31
tcp_autocorking - BOOLEAN
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 1a2506f795d4..3a34e9768bff 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -37,6 +37,7 @@ static int ip_local_port_range_min[] = { 1, 1 };
static int ip_local_port_range_max[] = { 65535, 65535 };
static int tcp_adv_win_scale_min = -31;
static int tcp_adv_win_scale_max = 31;
+static int tcp_app_win_max = 31;
static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS;
static int tcp_min_snd_mss_max = 65535;
static int ip_privileged_port_min;
@@ -1115,6 +1116,8 @@ static struct ctl_table ipv4_net_table[] = {
.maxlen = sizeof(u8),
.mode = 0644,
.proc_handler = proc_dou8vec_minmax,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = &tcp_app_win_max,
},
{
.procname = "tcp_adv_win_scale",