5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jakub Raczynski j.raczynski@samsung.com
[ Upstream commit 0e629694126ca388916f059453a1c36adde219c4 ]
When using publicly available tools like 'mdio-tools' to read/write data from/to network interface and its PHY via mdiobus, there is no verification of parameters passed to the ioctl and it accepts any mdio address. Currently there is support for 32 addresses in kernel via PHY_MAX_ADDR define, but it is possible to pass higher value than that via ioctl. While read/write operation should generally fail in this case, mdiobus provides stats array, where wrong address may allow out-of-bounds read/write.
Fix that by adding address verification before read/write operation. While this excludes this access from any statistics, it improves security of read/write operation.
Fixes: 080bb352fad00 ("net: phy: Maintain MDIO device and bus statistics") Signed-off-by: Jakub Raczynski j.raczynski@samsung.com Reported-by: Wenjing Shan wenjing.shan@samsung.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/mdio_bus.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index e5c25beae21e0..931b9a6c5dc50 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -565,6 +565,9 @@ int __mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+ if (addr >= PHY_MAX_ADDR) + return -ENXIO; + if (bus->read) retval = bus->read(bus, addr, regnum); else @@ -593,6 +596,9 @@ int __mdiobus_write(struct mii_bus *bus, int addr, u32 regnum, u16 val)
WARN_ON_ONCE(!mutex_is_locked(&bus->mdio_lock));
+ if (addr >= PHY_MAX_ADDR) + return -ENXIO; + if (bus->write) err = bus->write(bus, addr, regnum, val); else