serial: core: do fallible allocations before the console can be registered

serial_core_add_one_port() allocates uport->tty_groups after
uart_configure_port(), which may register the console. If the allocation
fails, the driver unwinds the port while its console remains registered.
The earlier uport->name allocation has a related failure path that leaves
state->uart_port linked to a port being freed.

Failslab reproduced a NULL dereference in PL011 console output and a KASAN
use-after-free in i.MX console output after failed binds.

Allocate the name and tty_groups before linking the port and configuring
it. Reserve space for the optional driver attribute group because
config_port() may populate uport->attr_group during configuration.

Fixes: 266dcff03eed ("Serial: allow port drivers to have a default attribute group")
Fixes: f7048b15900f ("tty: serial_core: Add name field to uart_port struct")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/all/20260719070454.D6FA21F000E9@smtp.kernel.org/
Assisted-by: Claude:claude-fable-5
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Link: https://patch.msgid.link/20260731181844.11330-2-kmehltretter@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions