There are several error handling bugs in mscc_ocelot_init_ports(). I
went through the code, and carefully audited it and made fixes and
cleanups.
1) The ocelot_probe_port() function didn't have a mirror release function
so it was hard to follow. I created the ocelot_release_port()
function.
2) In the ocelot_probe_port() function, if the register_netdev() call
failed, then it lead to a double free_netdev(dev) bug. Fix this by
setting "ocelot->ports[port] = NULL" on the error path.
3) I was concerned that the "port" which comes from of_property_read_u32()
might be out of bounds so I added a check for that.
4) In the original code if ocelot_regmap_init() failed then the driver
tried to continue but I think that should be a fatal error.
5) If ocelot_probe_port() failed then the most recent devlink was leaked.
The fix for mostly came Vladimir Oltean. Get rid of "registered_ports"
and just set a bit in "devlink_ports_registered" to say when the
devlink port has been registered (and needs to be unregistered on
error). There are fewer than 32 ports so a u32 is large enough for
this purpose.
6) The error handling if the final ocelot_port_devlink_init() failed had
two problems. The "while (port-- >= 0)" loop should have been
"--port" pre-op instead of a post-op to avoid a buffer underflow.
The "if (!registered_ports[port])" condition was reversed leading to
resource leaks and double frees.
Fixes: 6c30384eb1 ("net: mscc: ocelot: register devlink ports")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/YBkXhqRxHtRGzSnJ@mwanda
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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