net: mdio: fix undefined behavior in bit shift for __mdiobus_register
authorGaosheng Cui <cuigaosheng1@huawei.com>
Mon, 31 Oct 2022 13:26:45 +0000 (21:26 +0800)
committerJakub Kicinski <kuba@kernel.org>
Thu, 3 Nov 2022 03:30:51 +0000 (20:30 -0700)
commit40e4eb324c59e11fcb927aa46742d28aba6ecb8a
tree3f0707a7efad4a36dede796a4d18951e25dfe717
parentdac1dc7e4dc11fb9d9c35c50beba6b77f46fda6f
net: mdio: fix undefined behavior in bit shift for __mdiobus_register

Shifting signed 32-bit value by 31 bits is undefined, so changing
significant bit to unsigned. The UBSAN warning calltrace like below:

UBSAN: shift-out-of-bounds in drivers/net/phy/mdio_bus.c:586:27
left shift of 1 by 31 places cannot be represented in type 'int'
Call Trace:
 <TASK>
 dump_stack_lvl+0x7d/0xa5
 dump_stack+0x15/0x1b
 ubsan_epilogue+0xe/0x4e
 __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
 __mdiobus_register+0x49d/0x4e0
 fixed_mdio_bus_init+0xd8/0x12d
 do_one_initcall+0x76/0x430
 kernel_init_freeable+0x3b3/0x422
 kernel_init+0x24/0x1e0
 ret_from_fork+0x1f/0x30
 </TASK>

Fixes: 4fd5f812c23c ("phylib: allow incremental scanning of an mii bus")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20221031132645.168421-1-cuigaosheng1@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/phy/mdio_bus.c