From: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx> [ Upstream commit 40e4eb324c59e11fcb927aa46742d28aba6ecb8a ] 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@xxxxxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Link: https://lore.kernel.org/r/20221031132645.168421-1-cuigaosheng1@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/phy/mdio_bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 0fa6e2da4b5a..2aecc5ee9133 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -335,7 +335,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner) bus->reset(bus); for (i = 0; i < PHY_MAX_ADDR; i++) { - if ((bus->phy_mask & (1 << i)) == 0) { + if ((bus->phy_mask & BIT(i)) == 0) { struct phy_device *phydev; phydev = mdiobus_scan(bus, i); -- 2.35.1