tcp: restrict net.ipv4.tcp_app_win
authorYueHaibing <yuehaibing@huawei.com>
Thu, 6 Apr 2023 06:34:50 +0000 (14:34 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 20 Apr 2023 10:35:08 +0000 (12:35 +0200)
commit9d7765638fd8034e6861e90b3d4a47faea04b732
treebde7b04e624de553bd4464e3dbd61980bf39d48a
parent53a22fa7f9c20e77af9769e7f555c3fde6379704
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>
Documentation/networking/ip-sysctl.rst
net/ipv4/sysctl_net_ipv4.c