net: usb: rtl8150: don't incorrectly assign random MAC addresses
authorAnant Thazhemadam <anant.thazhemadam@gmail.com>
Sun, 11 Oct 2020 17:30:30 +0000 (23:00 +0530)
committerJakub Kicinski <kuba@kernel.org>
Sun, 18 Oct 2020 19:57:30 +0000 (12:57 -0700)
commit60f1626f0f866809de801724c3d180a9f322841e
tree23cddf68a1ca7cc7d46ef51f572fc3e2696fb2be
parent71a0e29e99405d89b695882d52eec60844173697
net: usb: rtl8150: don't incorrectly assign random MAC addresses

In set_ethernet_addr(), if get_registers() succeeds, the ethernet address
that was read must be copied over. Otherwise, a random ethernet address
must be assigned.

get_registers() returns 0 if successful, and negative error number
otherwise. However, in set_ethernet_addr(), this return value is
incorrectly checked.

Since this return value will never be equal to sizeof(node_id), a
random MAC address will always be generated and assigned to the
device; even in cases when get_registers() is successful.

Correctly modifying the condition that checks if get_registers() was
successful or not fixes this problem, and copies the ethernet address
appropriately.

Fixes: b2a0f274e3f7 ("net: rtl8150: Use the new usb control message API.")
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Link: https://lore.kernel.org/r/20201011173030.141582-1-anant.thazhemadam@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/usb/rtl8150.c