From: Nikita Kiryushin kiryushin@ancud.ru
[ Upstream commit 32fa4366cc4da1c97b725a0066adf43c6b298f37 ]
read_poll_timeout inside phy_read_poll_timeout can set val negative in some cases (for example, __mdiobus_read inside phy_read can return -EOPNOTSUPP).
Supposedly, commit 4ec732951702 ("net: phylib: fix phy_read*_poll_timeout()") should fix problems with wrong-signed vals, but I do not see how as val is sent to phy_read as is and __val = phy_read (not val) is checked for sign.
Change val type for signed to allow better error handling as done in other phy_read_poll_timeout callers. This will not fix any error handling by itself, but allows, for example, to modify cond with appropriate sign check or check resulting val separately.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration") Signed-off-by: Nikita Kiryushin kiryushin@ancud.ru Reviewed-by: Russell King (Oracle) rmk+kernel@armlinux.org.uk Link: https://lore.kernel.org/r/20240315175052.8049-1-kiryushin@ancud.ru Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/phy_device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 3ad9bbf65cbeb..6125418ca93f3 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -2706,8 +2706,8 @@ EXPORT_SYMBOL(genphy_resume); int genphy_loopback(struct phy_device *phydev, bool enable) { if (enable) { - u16 val, ctl = BMCR_LOOPBACK; - int ret; + u16 ctl = BMCR_LOOPBACK; + int ret, val;
ctl |= mii_bmcr_encode_fixed(phydev->speed, phydev->duplex);